Chapter III: THE GENERAL NATURALIST TYPE.--As Ray (d. 1705) and Linnæus (d

1778) began to reduce to order the accumulations of the encyclopædists, and as the anatomists and physiologists began the precise study of structure and function, the naturalist-travellers became more definite in their aims and more accurate in their observations. Linnæus himself sent several of his pupils on precisely scientific journeys. Moreover, in the eighteenth century there were not a few expeditions of geographical and physical purpose which occasionally condescended to take a zoologist on board. Thus Captain Cook was accompanied on his first voyage (1768-1781) by Banks and Solander, and on his second voyage by the Forsters, father and son. On his third voyage he expressly forbade the intrusion of any naturalist, but from all that we can gather it would have been better for himself if he had not done so. In these combined voyages there was nascent the idea of co-operative expeditions, of which the greatest has been that of the _Challenger_.

In illustration of travellers who were not specialists, but in varying degrees widely interested naturalists, it will be sufficient to cite three names--Thomas Pennant, Peter Pallas, and, greatest of all, Alexander von Humboldt.

Of Thomas Pennant (1726-1798) we may note that he was one of the early travellers in Scotland, which was then, as he says, almost as unknown as Kamchatka, and that he extorted from Dr. Johnson the admission, “He’s a Whig, sir, a sad dog; but he’s the best traveller I ever read; he observes more things than any one else does”. He knew Buffon and corresponded with Linnæus, and was the author of several works on British and North American zoology. His so-called _Arctic Zoology_ is mainly a sketch of the fauna in the northern regions of North America, begun “when the empire of Great Britain was entire, and possessed the northern part of the New World with envied splendour”. His perspective is excellent! the botanist, the fossilist, the historian, the geographer must, he says, accompany him on his zoological tours, “to trace the gradual increase of the animal world from the scanty pittance given to the rocks of Spitzbergen to the swarms of beings which enliven the vegetating plains of Senegal; to point out the causes of the local niggardness of certain places, and the prodigious plenty in others”. It was about the same time (1777) that E. A. W. Zimmermann, Professor of Mathematics at Brunswick, published a quarto in Latin, entitled _Specimen Zoologiæ Geographicæ Quadrupedum_, “with a most curious map”, says Pennant, “in which is given the name of every animal in its proper climate, so that a view of the whole quadruped creation is placed before one’s eyes, in a manner perfectly new and instructive”. It was wonderful then, but the map in question looks commonplace enough nowadays.

Peter Simon Pallas (1741-1811) was a student of medicine and natural science, and did good work as a systematic and anatomical zoologist. He was the first, we believe, to express the relationships of animals in a genealogical tree, but his interest for us here lies in his zoological exploration of Russia and Siberia, the results of which are embodied in a series of bulky volumes, admirable in their careful thoroughness. We rank him rather as one of the forerunners of Humboldt than as a zoologist, for his services to ethnology and geology were of great importance. He pondered over the results of his explorations, and many of his questionings in regard to geographical distribution, the influence of climate, the variation of animals, and similar problems, were prophetic of the light which was soon to dawn on biological science.

Alexander von Humboldt (1769-1859) was undoubtedly one of the greatest naturalists of the century which his life well nigh covered. Geologist, botanist, zoologist, and more, he was almost the last of the all-round naturalists. In this indeed lay his weakness as well as his strength, for great breadth of view is apt to imply a lack of precision as to details. In boyhood, “when life”, as he says, “appears an unlimited horizon”, he had strong desires after travel, which were in part gratified by excursions with George Forster and by Swiss explorations with the sagacious old geographer Leopold von Buch. These, however, only whetted his enthusiasm for journeys with a larger radius. At length, after many discouragements, he sailed in 1799 from Corunna, with Aimé Bonpland as companion, and spent five years in exploring the equinoctial regions of the New World. The full record of his voyage one cannot be expected to read, for there are about thirty volumes of it in the complete edition, but what we should all know is Humboldt’s _Personal Narrative_, in which the chief results of his explorations are charmingly set forth. Later in life (1829) he went with Ehrenberg and Rose to North Asia, and his crowning work was the publication of _Cosmos_ (1845-58), which originated in a series of lectures delivered in the University of Berlin. In front of that building his statue now stands, along with that of his not less famous brother Wilhelm.

We think of Humboldt not so much as an early explorer of tropical America, nor because he described the habits of the condor and made observations on electric eels, nor because he furnished Cuvier and Latreille with many new specimens, but rather as a magnificent type of the naturalist-traveller, observant, widely interested, and thoughtful, who pointed forward to Darwin in the success with which he realized the complexity of inter-relations in nature. Many a traveller, even among his contemporaries, discovered more new plants and animals than the author of _Cosmos_, but none approached him as an all-round naturalist, able to look out on all orders of facts with keenly intelligent eyes, a man, moreover, in whom devotion to science never dulled poetic feeling. His work is of real importance in the history of geographical distribution, for he endeavoured to interpret the peculiarities of the various faunas in connection with the peculiar environment of the different regions--a consideration which is at least an element in the solution of some of the problems of distribution. It is especially important in regard to plants, and one may perhaps say that Humboldt, by his vivid pictures of the vegetable “physiognomy” of different regions, and by his observations on the relations between climate and flora, laid the foundations of the scientific study of the geographical distribution of plants. We find in some of his _Charakterbilder_, for example in his _Views of Nature_, the prototype of those synthetic pictures which give Brehm’s popular lectures their peculiar interest and value.