Chapter VI: Conclusions (4)

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_Sexual differences, Mane._--The males of some species of Pinnipeds have a mane, i. e. the hairs of the neck are longer than on the rest of the body. Of _Eumetopias Stelleri_ “the hair is longest on the anterior upper portion of the body, where on the neck and shoulders it attains a length of 40 mm.; it decreases in length posteriorly, and toward the tail has a length of only 15 mm.” (ALLEN, _Hist. N. Am. Pinn._ p. 234). Of the hairs of _Callorhinus ursinus_ we read: “It is longest on the top of the head, especially in the males, which have a well marked crest. The hair is much longer on the anterior half of the body than on the posterior half, it being longest on the hinder part of the neck, where in the males it is very coarse. On the crown the hair has a length of 42 mm.; on the hinder part of the neck it reaches a length of 50 to 60 mm. From this point posteriorly it gradually shortens, and near the tail has a length of only 20 mm. The males have much longer hair than the females, in which it is much longer than in _Eumetopias Stelleri_.” (ALLEN, _Hist. N. Am. Pinn._ p. 315).

The difference in size of males and females is also a peculiar character of some species of Pinnipeds, as may be seen from the following tables:

+----------------------------+---------+---------+-------+
| | VERY OLD| VERY OLD| |
| NAME | MALE. | FEMALE.| RATIO.|
+----------------------------+---------+---------+-------+
|_Zalophus californianus_ | 8¹⁄₃ ft.| 6³⁄₄ ft.|100:81 |
|_Eumetopias Stelleri_ |13 „ | 9 „ |100:69 |
|_Macrorhinus leoninus_ |25 „ |15 „ |100:60 |
|_Macrorhinus angustirostris_|22 „ |13 „ |100:59 |
|_Callorhinus ursinus_ | 8 „ | 4 „ |100:50.|
+----------------------------+---------+---------+-------+

In _Callorhinus ursinus_ the female, as we observe, attains only half the length of a male. The weight of a fullgrown female being less than one sixth that of a full-grown male.

The losing of hair when the animals grow very old, is very striking in both _Odobaenus rosmarus_ and in _Odobaenus obesus_.

_Food._ The food of all Pinnipeds consists of mussels, and other mollusks, especially, however, of all kinds of fish, but that they are not averse to cetacean flesh, may be proved by the following fact: Mr. BROWN says of _Odobaenus rosmarus_: “I have only to add that whenever it was killed near where a whale’s carcass had been let adrift, its stomach was unvariably found _crammed_ full of the _krang_ or flesh of that _Cetacean_” (ALLEN, _Hist. N. Am. Pinn._ p. 135). _Eumetopias Stelleri_ occasionally eats birds (Ibid. p. 274).

_Breathing._--Even in seals and sea-lions it may be occasionally observed that they “blow like a whale”; I myself saw it more than once, when the animals lay with their nose at water level, or when they appeared on the surface after having remained under water for a long time. It is sufficiently known that the average time these animals remain under water is eight or ten minutes, but they have also been observed lying quite still on the bottom for more than three hours. I read in Mr. ALLEN’S work (p. 180) that also walruses “blow not unlike a whale”.

_Excretion._--The emitting a very strong odour is also known in Pinnipeds. KRASCHENINIKOW says of _Callorhinus ursinus_: “Such as are old, or have no mistresses, live apart; and the first that our people found upon _Behring_’s Island were such old ones, and all males, extremely fat and stinking” (ALLEN, p. 342). Of _Eumetopias Stelleri_ CHORIS reports: “L’odeur qu’ils répandent est insupportable. Ces animaux étaient alors dans le temps du rut” (ALLEN, p. 254), and of _Phoca foetida_ KUMLIEN asserts:

“It is only the adult males (called _Tigak_, = Stinker, by the Eskimo) that emit the horribly disagreeable, all-permeating, ever-penetrating odor that has suggested its specific name. It is so strong that one can smell an Eskimo some distance when he has been partaking of the flesh; they say it is more nourishing than the flesh of the females, and that a person can endure great fatigue after eating it. If one of these Tigak comes in contact with any other Seal meat it will become so tainted as to be repulsive to an educated palate; even the atluk of the Tigak can be detected by its odor.” (ALLEN, p. 624).

Respecting the foetid odour emitted by this species, Dr. RINK observes as follows:

“It derives its scientific name from the nauseous smell peculiar to certain older individuals, especially those captured in the interior ice-fjords, which are also on an average perhaps twice as large as those generally occurring off the outer shores. When brought into a hut, and cut up on its floor, such a seal emits a smell resembling something between that of assafoetida and onions, almost insupportable to strangers. This peculiarity is not noticeable in the younger specimens or those of a smaller size, such as are generally caught, and at all events the smell does not detract from the utility of the flesh over the whole of Greenland”.--_Danish Greenland, its People and its Products_ p. 123 (ALLEN, _Hist. N. Am. Pinn._ p. 624).

_Feeling._ Also in seals and sea-lions in our Zoological Gardens we may often observe that they dislike wind, and hold only the top of their nose above water, that they shut their eyes, and like to bask in the sun.

_Smell, Hearing, Sight._ It is also known of Pinnipeds that their smell is very good and their hearing very sharp, but that their sight is quite limited. This must not surprise us. Their eyes are adapted to see under water, but such eyes don’t see so well in the air. Yet I have observed that seals distinguish their keeper from other persons at a distance of twenty or thirty yards.

_Relative mobility of organs._ Every one who has ever witnessed the graceful movements of seals and sea-lions, especially those of _Zalophus californianus_ will admit that these animals, like sea-serpents, are “as limber and active as an eel”. There is not one movement made by the sea-serpent, which cannot be made in perfectly the same way by sea-lions, especially by _Zalophus californianus_, save the movement of the tail.

_Motion._ The same may be observed in comparing the motions of sea-serpents with those of _Zalophus californianus_. They too may appear on the surface, exposing head, neck, and so much of the forepart of the trunk, as to show their flappers; nay, they may like all kinds of whales, jump clear out of the water. When swimming slowly, they may occasionally swim with vertical undulations, they usually, however, propel themselves by means of their flappers, holding their body in a straight line; and sometimes horizontal undulations are distinctly visible; in darting on some prey they swim not only with their flappers, but undulate their body both horizontally and vertically at intervals. Of course generally only one or two, seldom three undulations are to be counted.

I don’t know if sea-lions have ever been seen swimming with _fixed bunches_, or folds. When at rest their skin may enormously wrinkle, like that of walruses, and as is shown in our fig. 78.

In swimming the sea-lion usually holds its head above water, and may occasionally raise its long neck as high as possible to take a view of a boat or another object.

Owing to the form and size of its flappers the speed of the sea-lion is really astonishing; it is much less in seals.

Though in a less degree, than in sea-serpents, the water curls up before its chest, or better throat, in swimming; foam is occasionally observed, and waves are seen in the form of a V, a wake is of course formed, and a rushing may be heard at times.

That seals swim so low under the surface of the water, that the course of the animal can be traced only by the rippling surface, I have myself witnessed, but I do not know if sea-lions, especially, if _Zalophus californianus_, are in the habit of swimming in this way.

The manner of disappearing of the sea-serpent is exactly the same as that of other Pinnipeds. They may turn down with a severe splash, or sink gradually below the surface, or even, by a sudden upward motion of their flappers, “sink down like a rock”.

As to the _voice_ of other Pinnipeds it is different in the different species, but as we have not a single statement of the voice of sea-serpents, comparison is out of the question here.

_Generation._--The rutting time and the time of whelping differ in different species, but on an average the month of March and April may be fixed upon as the pairing time, and July and August as those in which the females bring forth the young ones.

In some species the males are much larger than the females, and the new born young ones, like the young sea-serpents are in exact proportion to the old males, as may be seen from the following table.

+----------------------------+----------+----------+---------+
| NAME. | VERY OLD | NEW BORN | RATIO. |
| | MALE. |YOUNG ONE.| |
+----------------------------+----------+----------+---------+
|_Zalophus californianus_ | 8¹⁄₃ ft.| 2¹⁄₃ ft.| ¹⁄₃-¹⁄₄ |
|_Macrorhinus angustirostris_| 22 „| 4 „ | ¹⁄₅-¹⁄₆ |
|_Eumetopias Stelleri_ | 13 „| 2 „ | ¹⁄₆-¹⁄₇ |
|_Callorhinus ursinus_ | 8 „| 10 in. | ¹⁄₈-¹⁄₉ |
+----------------------------+----------+----------+---------+

_Taking notice of objects._ It is well enough known that seals will sometimes keep near a vessel, turning their head towards it; or will play round the vessel, disappearing on one side, reappearing on the other, as if playing hide and seek; from this it may be concluded they are in no dread of the vessel, but are curious, and suspicious of the living objects on it. I don’t know whether sea-lions and sea-bears behave in the same way, but I know that walruses do.

_Curiosity and Suspicion_ are known characters in all kinds of Pinnipeds, and it is noteworthy that they are most striking in walruses and seals.

_Harmlessness and Timidity._ There is hardly any Pinniped which is not harmless and timid.

_Fearlessness_ is a common trait in walruses and sea-elephants. One may come very near them. On the other hand scores of them, especially of the former, will sometimes follow a boat, roaring and crying and uttering the most horrible sounds, which may be expressions of their curiosity, suspicion, and fury, but it may also be a way they have of driving away their enemy.

_Fear_ on the contrary, though less noticeable in walruses, is a prominent trait in seals, sea-lions and sea-bears. When men approach them they fly away as fast as possible, and in their hurry to reach the water crawl over each other, and roar, and cry, and lament in a most horrible way.

_Fright._ It is superfluous to touch upon this subject in Pinnipeds; every one knows the effects and consequences of a shot at these timid animals.

_Fury._ As in sea-serpents, most Pinnipeds, but especially sea-lions, sea-bears and walruses only get furious when wounded, or when neared while they are protecting their offspring.

_Toughness._ I know of no observations about this character in seals, sea-lions, sea-bears, and sea-elephants, but I believe that they are not tough; one heavy blow with a thick cudgel on the nose killing them instantly, but the toughness of walruses is known well enough; these animals are not an easy prey; they may be struck with axes on their cranium and hit by several rifle balls in their brain, and yet not die; they die a hard death.

_Playsomeness_ is a well known character of all Pinnipeds; it may of course be less observable in the bulky and unwieldy walruses.

_Remark._ It is time that the volume comes to an end, and therefore I have made my comparison as short as possible. I have only to advise those who wish to know more about the agreement of sea-serpents with Pinnipeds, to read ALLEN’S often quoted work “_History of North-American Pinnipeds_”, and his “_On Eared Seals_”, (_Bull. Mus. Comp. Zool. Harvard College._ Cambr. Mass. Vol. II, n^o. 1.), and BREHM’S _Thierleben_.

There is one great difference between all the known Pinnipeds on one side, and sea-serpents on the other. The former are gregarious or social animals, only living in colonies or great herds, whilst _Megophias megophias_ is a solitary being. This remarkable difference can be only accounted for by the two facts 1. That this species is a cosmopolitan, and 2. That these animals become extinct and that there exist at present only a very few individuals.

I don’t know if I have convinced my readers of the existence of sea-serpents, and if so, if they are convinced that these animals are closely related to Pinnipeds. But I am obliged to proceed on my way, and consider the rank which sea-serpents occupy in the system of Nature.

2. ITS RANK IN THE SYSTEM OF NATURE.

Zoologists admit as a fact that Pinnipeds originate in true land-animals. We are convinced that these land-animals were long-tailed Viverrine animals. The tail must have been longer than one half of the total length. This is no impossibility, as we have still living forms, the tail of which is as long as half of the total length of the animal, e. g. _Herpestes Widdringtonii_. The dentition must have been the typical carnivorous one: i 3/3, c 1/1, m 7/7; or there were more molars, perhaps 8/8, as a genus of wild dogs, _Otocyon_, has 8 molars on each side of each jaw; its dentition is i 3/3, c 1/1, m 8/8. (The _Cynoidea_, or dog-like animals are also considered as having their origin in Viverrine animals.)

Some of the descendants of these long-tailed Viverrine animals had gradually got such characters, that zoologists would term them long-tailed Musteline animals. They may be called _long-tailed ancestors of weasels and stoats_, for our common weasel (_Putorius vulgaris_ L.) and our common stoat (_Putorius ermineus_ L.) are still living descendants of them, though the tail has become very short, most probably because they have accustomed themselves to live in holes. The long tail has shown itself to be an inconvenient organ for this new manner of living, and therefore has gradually become shorter.

Some of these _long-tailed ancestors of weasels and stoats_ took to another manner of living, compelled thereto by certain circumstances. They viz. took to eating fresh water fish. Gradually this grew to be a habit; they learned to swim, which happened by vertical undulations, they paddled with the feet, and used the tail as a rudder. This group may be called _long-tailed ancestors of polecats and minks_, for our common polecat (_Putorius putorius_ L.) and the Russian minks (_Putorius lutreolus_ L.) are still living descendants of them, though the tail has become short, because they have accustomed themselves to live in holes. The long tail has shown itself to be an inconvenient organ for such a manner of living, and therefore has gradually become shorter, not so short, however, as in weasels and stoats. Zoologists place the polecats and minks in the same genus as the weasels and stoats. The minks live especially in the neighbourhood of rivers and brooks, often go into the water and swim exceedingly well. Besides on poultry and rats, they feed on frogs, crabs, cray-fish, and all kinds of fish.

Some of these _long-tailed ancestors of polecats and minks_ got so used to the water, that it finally became their proper element, and they came ashore only to rest from swimming, to bask themselves in the sun, or to find another brook or river. They began to feed on fish, crayfish, and frogs, and only when driven by hunger they fed on rats and poultry. It is evident that those individuals which by nature were best adapted to their new element, must gradually have survived their less privileged brethren, and so we may admit that a form gradually arose, which swam very easily with vertical undulations, using the tail as a rudder and as propelling organ. Also of great advantage must have been more sharply pointed teeth, and more jagged molars, smaller ears, a more woolly skin, and toes on the hind limbs, which were capable of expansion and more or less provided with a web. This group may be called _long-tailed ancestors of otters_, for all the known species of otters (_Lutra_) are still living descendants of them, though the tail has become shorter, shorter than one third of the total length of the animal, because they too like to live in holes. The face greatly resembles that of the polecat and mink, but the upper lips are thicker and the whiskers are longer and stronger. The change was not only great enough for zoologists to create for this group a new genus: _Lutra_ STORR, but even to establish for it a new subfamily _Lutrina_ GRAY.

These _long-tailed ancestors of otters_ were again survived by their congeners which were still better adapted to the new medium, so that from them another group gradually arose, which had broader webs on the hind feet. This group may be called _long-tailed ancestors of fin-tailed otters_, for the fin-tailed otter (_Lutra Sanbachii_ GRAY) is a still living descendant of them. The tail of this animal is shorter than that of its ancestors, longer, however, than that of the otters (_Lutra_), surpassing one third of the animal’s total length. Moreover it is somewhat flattened and shows on its hindmost half lateral fin-like dilatations. The change was great enough for zoologists to place the animal into a new genus: _Pteronura_ GRAY. Its ancestors, however, were not provided with these lateral fin-like dilatations on the tail.

Some of these _long-tailed ancestors of the fin-tailed otter_ which in their migration had reached the sea-shore, probably by following the course of rivers, began to accustom themselves to eat sea-fish, and ended by feeding on them exclusively. The sea-water became their home, and their resting places and nests were found on the strand, and among sea-weed; they seldom came ashore to sleep or to sun themselves. Besides on sea-fish, they fed on crabs, lobsters, mussels, and some sea-weed. They left off eating poultry, frogs, and rats. The long tail was of great profit, as they used it as a rudder and as propelling organ in swimming with vertical undulations. Of course those individuals which were the best adapted to this new manner of living, survived the less privileged by nature, and so a group gradually arose which had a sharper dentition, and smaller ears; the skin was also changed to the most valuable fur, the toes of the hind-legs had become more webbed, and with such legs the animals could swim more easily; those of the fore-limbs had sharper nails, and with such nails the animals could more easily crawl upon the rocks; the eyes were larger, and with such eyes the owners could see better in great and dark depths, and in the sea-water near the shore, which is commonly troubled; the whiskers were longer and stronger, consequently the upper-lips, in which these whiskers were planted and which contained numerous and thick sensorial nerves, were very thick, and with such whiskers the animals could exceedingly well touch and feel when searching for their food between stones and sea-weed, and in the sandy bottom. The face resembled but little more that of the otters and fin-tailed otters, and the large eyes and shorter ears gave it a slight resemblance to seals. This group may be called _long-tailed ancestors of sea-otters_, for our sea-otters (_Lutra lutris_ L.) are still living descendants of them. But as these animals have accustomed themselves to live more among sea-weed, ice, and rocks than their direct ancestors, the long tail must have been inconvenient, so that individuals with a shorter tail must have survived the others, and finally a species arose with a tolerably short tail: our sea-otter. To make up for this loss of tail, the hind-feet had become more webbed, and were gradually stretched more backwards, and, modified in this way, they were valuable swimming organs. The change was great enough for zoologists to create a new genus for this animal, which is called _Enhydra_ CUV.

Some of the _long-tailed ancestors of sea-otters_ took to a still more aquatic, or better pelagic life, migrated more towards the north, accustomed themselves to the icy regions, to swim greater distances and to remain longer under water. The consequences of this change in the manner of living were that all little adapted to this new life became extinct, and that all which were better privileged survived them, so that at last a group of animals arose of which we may safely admit that they had the following characters: The head and fore-feet resembled still more those of seals, the hind-legs were still more able swimming organs, and less fit for terrestrial locomotion, they were smaller than the fore-legs, because they were not always used in swimming, as the best manner of swimming must have been by means of vertical undulations; the long tail surpassed half of the total length, and served as a rudder and as propelling organ; the ears were still smaller, the dentition was still a normal carnivorous one (i 3/3, c 1/1, m 7/7), especially the molars were sharp and pointed, and on the skull were found peculiar modifications which are so distinctly visible on that of Pinnipeds. The animals must have resembled our common seals, having, however, small external ears, and a tail, surpassing one half of the total length. It is difficult to believe that these animals, which I will call _Propinnipedia_, moved on land; probably they came from time to time aland or on the ice to rest with the fore-part of the body on it, leaving, however, most certainly the long tail in the water. These _Propinnipedia_ gave origin to two groups of animals, which are marked below with A and B.

A.--This group, by their having lived almost constantly far from land, and having come only very seldom near the shore to rest, supporting themselves on the chest or breast, clinging with the nails of the fore-legs to the beach, rock, or ice, changed in such a way, that zoologists can hardly reckon them any longer among Pinnipeds, but generally consider them as a link between Pinnipeds and Whales. Professor D’ARCY W. THOMPSON (_Studies from the Museum of Zoology in University College_, Dundee, Vol. I, N^o. 9, 1890) rejects any affinity of this group to Whales. I should like to go still farther and pretend that it has just as much claim to the title of Pinnipeds, as seals, sea-elephants, sea-bears, sea-lions, and sea-serpents. The skull was somewhat lengthened in front; the brain-case diminished in size; the deciduous dentition probably cut the gum; the permanent dentition was the typical heterodont carnivorous one (i 3/3, c 1/1, m 7/7); the nostrils were placed on the tip of the nose, as in seals, but directed upwards; the fore-limbs were perfectly those of seals, and provided with nails; but the rest of the body must have _resembled_ that of a slender and elongated dolphin, or whale, with an enormous _pointed_ tail. The most successful manner of swimming for these animals was by means of vertical undulations, which, as the forepart of the body (head and trunk) was somewhat bulky, and therefore somewhat inflexible, were strongest in the tail-part of the animal; consequently the hind-legs, used less and less, disappeared, if not quite, at least for the greater part. The animals were still hairy, though the hairs were most probably thinly scattered; the whiskers remained on the lips. The head was relatively large, not with regard to the animal’s total length, but to the trunk, and therefore the neck was very short. Externally the neck must not have been plainly visible. The animals could not move the head as easily as seals and sea-lions do, and therefore it was of great advantage that the nostrils were directed upwards. The vertebrae have the type of those of the Pinnipeds.--Such animals are now extinct, but their fossil remains are found and called _Basilosaurus_ by HARLAN in 1824 (afterwards OWEN gave them the name of _Zeuglodon_, 1839).

B.--This second group is called _Pinnipedia_ by ILLIGER in 1811, and ALLEN gives of it the following characters:

“Limbs pinniform, or modified into swimming organs, and enclosed to or beyond the elbows and knees within the common integument. Digits of the manus decreasing in length and size from the first to the fifth; of those of the pes, the first and fifth largest and longest, the three middle ones shorter and subequal. Pelvis with the iliac portion very short, and the anterior border much everted; ischia barely meeting by a short symphysis (never anchylosed) and in the female usually widely separated. Skull generally greatly compressed interorbitally; facial portion usually short, rather broad, and the brain-case abruptly expanded. Lachrymal bone imperforate and joined to the maxillary, enclosed wholly within the orbit. Palatines usually separated by a vacuity, often of considerable size, from the frontals. Tympanic bones separated also by a vacuity from the exoccipitals. Dentition simple, generally unspecialized, the molars all similar in structure. Deciduous dentition rudimentary, never truly functional, and generally not persistent beyond the foetal stage of the animal. Permanent incisors usually 6/4 or 4/4, sometimes 4/2 (_Cystophora_ and _Macrorhinus_) or even 2/2 (_Odobaenus_); canines 2/2; molars 5/5, 6/5, or 5/3.”

And we may add: Tail either very long: about as long as one half of the animal’s total length, or very short: almost disappearing between the hind-legs.

Already very early the Pinnipeds divided themselves into two different branches, marked below with I and II.

I.--The members of this branch changed their manner of living. They very often crawled on land, ice, and rocks; the long tail was a very unconvenient organ in their new manner of living, consequently all the individuals with a somewhat shorter tail than their congeners’ were better adapted to the new manner of living and survived them, so that at last a group of animals arose of which the tail has become very short, almost disappearing between the hind-legs, and to make up for this loss the hind-legs grew much larger than the fore-legs, were turned hindwards, gradually grew incapable of being turned forwards, and of no use in terrestrial locomotion. This branch is called _Inauriculata_ by PÉRON in 1816 (afterwards called _Phocidae_ by GRAY in 1825, and _Reptigrada_ by ELLIOT COUES, invited thereto by ALLEN in 1880). The characters are described by ALLEN as follows:

“Hind-legs not capable of being turned forward, and not serviceable for terrestrial locomotion. Neck short. Skull with the mastoid processes swollen, but not salient, and without distinct alisphenoid canals. Anterior limbs smaller than the posterior, the first digit little, if any, longer than the next succeeding ones, all armed with strong claws, which are terminal. Hind feet capable of moderate expansion, short; digits (usually) all armed with strong claws, and without terminal cartilaginous flaps. Femur with no trace of the trochanter minor. Without external ears. Postorbital processes wanting, or very small. Incisors variable (6/4, 4/4, or 4/2). Deciduous dentition not persistent beyond foetal life.”

The group includes all true seals and sea-elephants.

II.--This branch is called _Gressigrada_ by ELLIOT COUES in 1880, who was thereto invited by ALLEN, though this skilled zoologist was then unaware of the existence of the sea-serpent, or at least must have doubted its belonging to this branch. I have not a single reason to give another name to it; I purposely keep the name of _Gressigrada_, to avoid the increase of synonyms. The early forms of the _Gressigrada_ must have had hind-legs which were smaller than the fore-legs, and a tail, which was as long as the head, neck and trunk together. They had also small external ears, and a somewhat lengthened neck. Further characters are: “Hind-legs capable of being turned forward and used in terrestrial locomotion. Neck lengthened (especially in section b). Skull with the mastoid processes large and salient (especially in the males), and with distinct alisphenoid canals. Anterior feet either nearly as large as the posterior, or much larger, their digits rapidly decreasing in length from the first to the fifth, with distinct claws, and with a broad cartilaginous border extending beyond the digits.” (They are called flappers.) “Hind-feet susceptible of great expansion, the three middle digits only with claws, and all the digits terminating in long, narrow, cartilaginous flaps, united basally.” (The hind-feet may also safely be called flappers.) “Femur with the trochanter minor well developed”.--Already at a very early date the branch of the _Gressigrada_ divided itself into two sections, which are marked below with a and b.--

a.--The members of this section changed their manner of living. They very often crawled on ice, land, and rocks; the long tail was a very inconvenient organ in their new manner of living, consequently all the individuals with a somewhat shorter tail than their congeners’ were better equipped, and survived the others, so that at last a group of animals arose of which the tail has become very short, scarcely, if at all, visible, being enclosed within the tegument of the body, and to make up for this loss, the hind-flappers grew much larger than the fore-flappers. The further characters for this group are: “Without external ears. Form thick and heavy. Anterior portion of the skull greatly swollen, giving support to the enormously developed canines, which form long, protruding tusks. Incisors of deciduous (foetal) dentition 6/6; of permanent dentition 2/6. No postorbital processes, and the surface of the mastoid processes continuous with the auditory bullae.”--This section is called _Trichecidae_ by GRAY in 1821 (afterwards it was named _Trichechidae_ by GRAY in 1825, _Broca_ by LATREILLE in 1825, _Campodontia_ by BROOKES in 1828, _Trichecina_ by GRAY in 1837, _Trichechoidea_ by GIEBEL in 1847, _Trichechina_ by GRAY in 1850, _Rosmaridae_ by GILL in 1866, _Rosmaroidea_ by GILL in 1872, and _Odobaenidae_ by ALLEN in 1880!!!). The section contains only the walruses.

b.--The early forms of this section must have had hind-flappers which were smaller than the fore-flappers, and a tail which was as long as the head, neck and trunk together. The animals were very slender and elongated in form, the neck being _somewhat more elongated_; external ears, though small, were still present. Further characters are: “Anterior portion of the skull not unusually swollen, and the canines not highly specialized.” They came very seldom aland, and when doing so, they must have only supported themselves on their breast and on their fore-flappers, leaving the long tail always in the water. They swam with vertical undulations, using also sometimes the flappers.--For this section I choose the name of _Tenuia_, or Animals which are slender.--Very early the section of the _Tenuia_ divided itself into two smaller divisions which are marked below with 1 and 2.--

1.--The members of this division changed their manner of living. They very often crawled on ice, land and rocks; the tail was a very inconvenient organ in their new manner of living, consequently all the individuals with a somewhat shorter tail than their congeners’, were better equipped and survived the others, so that at last a group of animals arose of which the tail has become very short, almost disappearing between the hind-legs which on the contrary to make up for this loss of tail, gradually became larger, so as to become even larger than the anterior feet. The further characters of this group are: “With small external ears. Incisors of deciduous dentition 6/4, only the outer on either side cutting the gum; of permanent dentition 6/4, the two central pairs of the upper with a transverse groove. Postorbital processes strongly developed. Surface of the mastoid processes not continuous with the auditory bullae.”--This division was called _Auriculata_ by PÉRON in 1816, (afterwards also called _Otariina_ by GRAY in 1825, _Otariadae_ by BROOKES in 1828, _Arctocephalina_ by GRAY in 1837, and _Otariidae_ by GILL in 1866) containing the sea-bears and sea-lions.

2.--The members of this division did not accustom themselves to live in the midst of ice and rocks, consequently they retained the long tail, and small hind-legs. As the animals retained also their slenderness and extraordinary litheness, a long neck with a relatively small head must have been of great use to them, and consequently those individuals which had a longer neck than the others survived their less privileged congeners, so that at last a group arose with a very long neck and a comparatively small head. It seems that the external ears disappeared. They never came aland or on ice-floes. They even abandoned the cold regions and currents of the ocean, better liking the warmer parts. Their ordinary mode of swimming is with vertical undulations. Seldom do they swim with the body in a straight line, by means of their flappers. This little division for which I propose the name of _Longicaudata_, or Long-tailed Animals, consists only of one genus: _Megophias_ RAF., including only one species _Megophias megophias_ (RAF.) OUD., the sea-serpent.

I purposely have not mentioned the genera _Squalodon_ and _Stenodon_,
and the group of _Plagiuri_ (ART., 1735; _Physeteres_, KLEIN,
1741; _Cetacea_, BRISS, 1756; _Cete_, LINN, 1758), as the recent
cetologists still differ in opinions as to their relation to
_Basilosaurus_ and the _Pinnipedia_.

I think the following phylogenetic table will in a more practical
manner show the rank which in my opinion sea-serpents occupy in the
System of Nature.

To many of my readers the above sketch of the rank of the sea-serpent
in the System of Nature will no doubt seem to be too bold. They will
say that the affinity of the sea-serpent to sea-lions and sea-bears
(to the _Auriculata_) is expressed here too decisively, that,
scientifically spoken, the sea-serpent is not yet known, that at best
its existence is only beyond a doubt, and that when a specimen fell
into the hands of men, it might be shown that the close affinity to
the _Auriculata_ was only apparent, and that in reality the relation
is more remote. I confess that there is much to say in favour of this
reasoning, but _at all events the sea-serpent is a true Pinniped_.
It has four flappers, a hairy skin, and strong whiskers. Its head
_resembles_ that of a sea-lion, its long neck _resembles_ that of
a sea-lion, its trunk and its foreflappers _resemble_ those of a
sea-lion. But these _resemblances_ may be explained as resulting from
convergency. When viewed in this way it seems to be more careful to
consider the origin of the sea-serpent in the following manner.

The ancestors of _Pinnipedia_ and _Basilosaurus_, which I have called _Propinnipedia_, had most probably hind-legs which were smaller than the fore-legs, and most certainly a tail which was nearly as long as the head, neck and trunk together. They had small external ears. Their most successful manner of swimming must have been by means of vertical undulations. It is difficult to believe that the _Propinnipedia_ moved on land; probably they came only from time to time aland, or on the ice, to rest, leaving, however, most probably the long tail in the water. These _Propinnipedia_ divided themselves into two branches.

All the members of the _first_ branch got a tendency to bulkiness. The head grew longer and larger, consequently the neck grew shorter; the jaws grew longer, consequently the teeth began to stand widely apart; in consequence of the little mobility of the head the nostrils, placed at the top of the nose, became turned upwards, or probably got their seat a little more towards the top of the head; and in proportion as the animal got a thick layer of bacon, the hairs became thinly scattered. Probably it is here better to say: in proportion as the animal lost its hairs, it got a thick layer of bacon. The warm-blooded mammals are possessed of the hair, because hair was to them what feathers are to a bird. The air enclosed between the hairs and the feathers is a worse conductor of temperature than the hairs or feathers themselves. As soon as the manner of living has changed so much that air could no longer come between the hairs, the hairs themselves lost their reason of existence, hence a thick layer of bacon gradually replaced them. Probably this is a better way to explain the presence of bacon and the absence of hair, than to say that the hair disappeared because the animals obtained a layer of bacon, and could therefore dispense with them, or that the layer of bacon checked the development of hairs.--In short we may admit that the animals, of which we treat at present, were thinly scattered with hairs. The whiskers in all probability were still present, and even well developed. This branch has wholly become extinct. The fossil remains were called _Basilosaurus_.

All the members of the _second_ branch did not show a tendency to bulkiness, they retained the relatively small head and well developed neck, the head consequently could very well move on the trunk. These are the _Pinnipedia_.

Already very early they divided themselves into two sections.

All the members of the _first_ section accustomed themselves to crawl more on land, ice, and rocks, and as the long tail must have been an inconvenient organ in this new manner of living, all the individuals which had a smaller number of caudal vertebrae survived their congeners; consequently a form at last originated with a very short tail our well known order of Pinnipeds for which I now propose the name of _Brevicaudata_.

All the members however, of the second section accustomed themselves more to the sea, and therefore all the members which were best adopted for this manner of living successively survived their less privileged congeners, and finally the sea-serpents remained; animals which are so excellently adapted to an aquatic life and rapid movement, that their tendency to become extinct can only be explained by the singular phenomenon that colossal animals bring forth very few young ones, only two, or only one, at a time, and only after very long intervals. For these animals I already proposed above the name of _Longicaudata_. They form with the _Brevicaudata_ the order of _Pinnipedia_.

If this view is better, (and who will tell us this with any certainty?) the phylogenetic table should be altered as follows:

In the first table I have tried to show two things.

Firstly:--With a horizontal dotted line I have separated the still living animals or groups from those who have become extinct; the former are placed above, the latter beneath the dotted line.

And Secondly:--With the different lengths of the vertical dotted lines I have tried to show the different relative lengths of time-periods wanted by the different species or groups to be formed, so to speak, from that species or group which in this table is placed exactly beneath it, and with which it is united by a dotted line.

It is clear that the evolution must have happened, geologically spoken, with extreme rapidity there, where the animals were entirely changing their manner of living, be it from a terrestrial one into an aquatic one, or otherwise; and that the evolution happened less rapid, or even, geologically spoken, very slowly, where the animals remained terrestrial or aquatic beings, and only changed their manner of living in so far, that they became troglodytes or semi-troglodytes, or became from carnivorous only piscivorous or semi-carni-semi-piscivorous. I believe that by this hypothesis the problem is solved why remains of _Basilosaurus_ are already found in Eocene layers together with remains of Viverrine ancestors of _Carnivora_, _Pinnipedia_ and _Basilosaurus_, whilst those of true _Pinnipedia_, _Lutrina_ and _Mustelina_ appear for the first time during the Miocene period, and whilst remains of true _Viverra_’s (the genus) do not seem to have made their appearance before the Pliocene period.

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The great sea-serpentChapter VI: Conclusions (4)

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