Chapter VII: Part II: New Data (4)

+---------------------+-----------------------------------+------+
|Gens. | Classes. | |
+---------------------+--------+--------+--------+--------+ |
| | y w | y b_1| y w b_1| y |Total.|
| | -------| -+-----| ---+---| -+--+--| |
| | b_1| w | | w b_1 | |
| +--------+--------+--------+--------+------+
|Yellow white x bifid.| 233 254| 1 2 | 10 6 | .. .. | 506 |
| +========+========+========+========+======+
| | y | y v B' | y B'| y v | |
| | -------| -+-----| ---+---| -+--+--| |
| | v B'| | v | B'| |
|Yellow x vermilion +--------+--------+--------+--------+------+
|bar. | 99 101 | 60 55 | 49 48 | 9 14 | 435 |
| +========+========+========+========+======+
| | w b_1 | w f| w b_1 f| w | |
| | -------| -+-----| ---+---| -+--+--| |
| | f| b | | b_1 f| |
| +--------+--------+--------+--------+------+
|White bifid x forked.| 84 77 | 9 6 | 65 59 | 1 5 | 306 |
| +========+========+========+========+======+
| | v m | v s| v m s| v | |
| | -------| -+-----| ---+---| -+--+--| |
| | s| m | | m s| |
|Vermilion miniature +--------+--------+--------+--------+------+
|x sable. | 152 111| 4 2 | 5 12 | .. ..| 286 |
| +========+========+========+========+======+
| | s r | s f| s r f| s | ~
| | -------| -+-----| ----+--| -+--+--| ~
| | f| r | | r f| |
|Sable rudimentary x +--------+--------+--------+--------+------+
|forked. | 143 195| 26 27 | 4 3 | .. ..| 398 |
+---------------------+--------+--------+--------+--------+------+
| WHITE BIFID x RUDIMENTARY. |
+---------------------+-----------------------------------+------+
| F_{2} females. | F_{2} males. | |
+--------+------------+--------+--------+--------+--------+ |
|w b_1 | w | w b_1 | w r | w b_1 r| w |Total.|
|------- | --+--- | -------| -+--- | -----+-| +---+- | |
| | b_1 | r | b_1 | | b_1 r | |
+--------+------------+--------+--------+--------+--------+------+
|228 335 | 15 11 | 150 66 | 2 10 | 29 135| 2 1 | 395 |
+--------+------------+--------+--------+--------+--------+------+
| WHITE BIFID x MINIATURE RUDIMENTARY. |
+--------+------------+--------+--------+--------+--------+------+
|w b_1 | w | | | | | |
|------- | --+--- | ------ | -+--- | ---+---| -----+-|-+-+--|
| | b_1 | | | | | |
+--------+------------+--------+--------+--------+--------+------+
| 344 | 31 | 109 | 2 | 58 | 41 | 2 |
+--------+------------+--------+--------+--------+--------+------+

+--------------------------------------+
| Cross-over values. |
+------------+------------+------------+
| Yellow | White | Yellow |
| white. | bifid. | bifid. |
| | | |
+------------+------------+------------+
| 0.6 | 3.2 | 3.8 |
+============+============+============+
| Yellow |Vermilion | Yellow |
|vermilion. | bar. | bar. |
| | | |
+------------+------------+------------+
| 32 | 28 | 49 |
+============+============+============+
| White | Bifid | White |
| bifid. | forked. | forked. |
| | | |
+------------+------------+------------+
| 7 | 42 | 45 |
+============+============+============+
| Vermilion |Miniature |Vermilion |
| miniature. | sable. | sable. |
| | | |
+------------+------------+------------+
| 2.1 | 6 | 8.1 |
+============+============+============+
~ Sable |Rudimentary | Sable |
~rudimentary.| forked. | forked. |
| | | |
+------------+------------+------------+
| 13.3 | 1.8 | 15 |
+------------+------------+------------+
| WHITE BIFID x RUDIMENTARY. |
+--------------------------------------+
| Cross-over values. |
+------------+------------+------------+
| White | Bifid | White |
| bifid. |rudimentary.|rudimentary.|
| | | |
+------------+------------+------------+
| 3.8 | 42.3 | 44.5 |
+------------+------------+------------+
| WHITE BIFID x MINIATURE RUDIMENTARY. |
+------------+------------+------------+
| | | |
| -+--+- | ---+-+- | -+-+-+- |
| | | |
+------------+------------+------------+
| 0 | 6 | 1 |
+------------+------------+------------+

{82}

SUMMARY OF THE PREVIOUSLY DETERMINED CROSS-OVER VALUES.

The data of the earlier papers, namely, Dexter, 1912; Morgan, 1910_c_, 1911_a_, 1911_f_, 1912_f_, 1912_g_; Morgan and Bridges, 1913; Morgan and Cattell, 1912 and 1913; Safir, 1913; Sturtevant, 1913 and 1915; and Tice, 1914, have been summarized in a recent paper by Sturtevant (Sturtevant, 1915) and are given here in table 64. Our summary combines three summaries of Sturtevant, viz, that of single crossing-over and two of double crossing-over.

TABLE 64.--_Previously published data summarized from Sturtevant, 1915_.

+------------------------+--------+-------------+------------+
| Factors. | Total. | Cross-overs.| Cross-over |
| | | | values. |
+------------------------+--------+-------------+------------+
| Yellow white. | 46,564 | 498 | 1.07 |
| Yellow vermilion. | 10,603 | 3,644 | 33.4 |
| Yellow miniature. | 18,797 | 6,440 | 34.3 |
| Yellow rudimentary. | 2,563 | 1,100 | 42.9 |
| Yellow bar. | 191 | 88 | 46.1 |
| White vermilion. | 15,257 | 4,910 | 32.1 |
| White miniature. | 41,034 | 13,513 | 32.8 |
| White rudimentary. | 5,847 | 2,461 | 42.1 |
| White bar. | 5,151 | 2,267 | 44.0 |
| Vermilion miniature. | 5,329 | 212 | 4.0 |
| Vermilion rudimentary. | 1,554 | 376 | 24.1 |
| Vermilion bar. | 7,514 | 1,895 | 25.2 |
| Miniature rudimentary. | 12,567 | 2,236 | 17.8 |
| Miniature bar. | 3,112 | 636 | 20.4 |
| Rudimentary bar. | 159 | 7 | 4.4 |
+------------------------+--------+-------------+------------+

{83}

SUMMARY OF ALL DATA UPON LINKAGE OF GENS IN CHROMOSOME I.

In table 65 all data so far secured upon the sex-linked characters are summarized. These data include the experiments previously published in the papers given in the bibliography and the experiments given here. The data from experiments involving three or more loci are calculated separately for each value and included in the totals.

TABLE 65.--_A summary of all linkage data upon chromosome I_.

+----------------------------+----------+--------------+------------+
| Gens. | Total. | Cross-overs. | Cross-over |
| | | | values. |
+----------------------------+----------+--------------+------------+
| Yellow lethal 1. | 131 | 1 | 0.8 |
| Yellow lethal 1_b_. | 744 | 6 | 0.8 |
| Yellow white. | 81,299 | 875 | 1.1 |
| Yellow abnormal. | 15,314 | 299 | 2.0 |
| Yellow bifid. | 3,681 | 201 | 5.5 |
| Yellow club. | 525 | 93 | 17.7 |
| Yellow vermilion. | 13,271 | 4,581 | 34.5 |
| Yellow miniature. | 21,686 | 7,559 | 34.3 |
| Yellow sable. | 1,600 | 686 | 42.9 |
| Yellow rudimentary. | 2,563 | 1,100 | 42.9 |
| Yellow bar. | 626 | 300 | 47.9 |
| Lethal 1 white. | 1,763 | 7 | 0.4 |
| Lethal 1 miniature. | 814 | 323 | 39.7 |
| Lethal 1_b_ white. | 846 | 0 | 0.0 |
| White facet. | 666 | 7 | 1.1 |
| White abnormal. | 16,300 | 277 | 1.7 |
| White bifid. | 23,595 | 1,260 | 5.3 |
| White lethal 2. | 8,011 | 767 | 9.6 |
| White club. | 2,251 | 321 | 14.3 |
| White lethal _sb_. | 3,678 | 572 | 15.6 |
| White lemon. | 241 | 35 | 14.5 |
| White depressed. | 59 | 12 | 20.3 |
| White lethal _sa_. | 1,150 | 256 | 22.2 |
| White vermilion. | 27,962 | 8,532 | 30.5 |
| White reduplicated. | 418 | 121 | 28.9 |
| White miniature. | 110,701 | 31,071 | 33.2 |
| White furrowed. | 208 | 63 | 30.3 |
| White sable. | 2,511 | 1,032 | 41.2 |
| White rudimentary. | 6,461 | 2,739 | 42.4 |
| White forked. | 3,664 | 1,676 | 45.7 |
| White bar. | 5,955 | 2,601 | 43.6 |
| White fused. | 430 | 186 | 43.3 |
| White lethal _sc_. | 3,053 | 1,406 | 46.0 |
| Facet vermilion. | 852 | 278 | 32.6 |
| Facet sable. | 186 | 80 | 43.0 |
| Bifid vermilion. | 2,724 | 849 | 31.1 |
| Bifid miniature. | 219 | 67 | 30.6 |
| Bifid rudimentary. | 899 | 384 | 42.7 |
| Bifid forked. | 306 | 130 | 42.5 |
| Lethal 2 vermilion. | 1,400 | 248 | 17.7 |
| Lethal 2 miniature. | 6,752 | 1,054 | 15.4 |
| Club lethal 3. | 222 | 29 | 13.0 |
| Club vermilion. | 5,558 | 1,047 | 18.8 |
| Lethal _sb_ miniature. | 3,678 | 733 | 19.9 |
| Lemon vermilion. | 241 | 29 | 12.0 |
{84}
| Shifted vermilion. | 1,007 | 155 | 15.5 |
| Shifted bar. | 242 | 76 | 31.4 |
| Depressed vermilion. | 59 | 10 | 17.0 |
| Depressed bar. | 464 | 176 | 38.0 |
| Lethal 3 vermilion. | 1,549 | 105 | 6.8 |
| Lethal 3 miniature. | 1,481 | 138 | 9.3 |
| Vermilion dot. | 57 | 0 | 0.0 |
| Vermilion reduplicated. | 667 | 11 | 1.7 |
| Vermilion miniature. | 10,155 | 317 | 3.1 |
| Vermilion furrowed. | 240 | 9 | 3.8 |
| Vermilion sable. | 9,209 | 929 | 10.1 |
| Vermilion rudimentary. | 1,554 | 376 | 24.1 |
| Vermilion forked. | 665 | 163 | 24.5 |
| Vermilion bar. | 23,522 | 5,612 | 23.9 |
| Vermilion fused. | 9,252 | 2,390 | 25.8 |
| Reduplicated bar. | 583 | 120 | 20.6 |
| Miniature furrowed. | 208 | 7 | 3.4 |
| Miniature sable. | 1,855 | 125 | 6.7 |
| Miniature rudimentary. | 12,786 | 2,284 | 17.9 |
| Miniature bar. | 3,112 | 636 | 20.5 |
| Furrowed sable. | 209 | 12 | 5.7 |
| Furrowed forked. | 209 | 40 | 19.1 |
| Furrowed bar. | 240 | 43 | 17.9 |
| Sable rudimentary. | 663 | 95 | 14.3 |
| Sable forked. | 872 | 140 | 16.0 |
| Sable bar. | 7,524 | 1,036 | 13.8 |
| Sable lethal _sc_. | 1,641 | 387 | 23.6 |
| Rudimentary forked. | 1,456 | 20 | 1.4 |
| Rudimentary bar. | 664 | 15 | 2.3 |
| Forked bar. | 1,706 | 8 | 0.5 |
| Forked fused. | 1,201 | 37 | 3.1 |
| Bar fused. | 8,768 | 222 | 2.5 |
| Bar lethal _sc_. | 1,734 | 144 | 8.3 |
+----------------------------+----------+--------------+------------+

* * * * *

{85}

BIBLIOGRAPHY.

BRIDGES, CALVIN B.

1913. Non-disjunction of the sex-chromosomes of _Drosophila_. Jour.
Exp. Zool., 15, p. 587, Nov. 1913.

1914. Direct proof through non-disjunction that the sex-linked gens of
_Drosophila_ are borne by the X chromosome. Science, 40, p. 107, July
17, 1914.

1915. A linkage variation in _Drosophila_. Jour. Exp. Zool., 19, p. 1.
July 1915.

1916. Non-disjunction as proof of the chromosome theory of heredity.
First instalment, Genetics I, p. 1-52; second instalment, Genetics I,
No. 2, 107-164.

CHAMBERS, R.

1914. Linkage of the factor for bifid wing. Biol. Bull. 27, p. 151,
Sept. 1914.

DEXTER, JOHN S.

1912. On coupling of certain sex-linked characters in _Drosophila_.
Biol. Bull. 23, p. 183, Aug. 1912.

1914. The analysis of a case of continuous variation in _Drosophila_ by
a study of its linkage relations. Am. Nat., 48, p. 712, Dec. 1914.

DUNCAN, F. N.

1915. An attempt to produce mutations through hybridization. Am. Nat.,
49, p. 575, Sept. 1915.

HOGE, M. A.

1915. The influence of temperature on the development of a Mendelian
character. Jour. Exp. Zool., 18, p. 241.

MORGAN, T. H.

1910a. Hybridization in a mutating period in _Drosophila_. Proc. Soc.
Exp. Biol. and Med., p. 160, May 18, 1910.

1910b. Sex-limited inheritance in _Drosophila_. Science 32, p. 120,
July 22, 1910.

1910c. The method of inheritance of two sex-limited characters in the
same animal. Proc. Soc. Exp. Biol. and Med., 8, p. 17.

1911a. An alteration of the sex-ratio induced by hybridization. Proc.
Soc. Exp. Biol. and Med., 8, No. 3.

1911b. The origin of nine wing mutations in _Drosophila_. Science, 33,
p. 496, Mar. 31, 1911.

1911c. The origin of five mutations in eye-color in _Drosophila_, and
their mode of inheritance. Science, April 7, 1911, 33, P. 534.

1911d. A dominant sex-limited character. Proc. Soc. Exp. Biol. and
Med., Oct. 1911.

1911e. Random segregation _versus_ coupling in Mendelian inheritance.
Science, 34, p. 384, Sept. 22, 1911.

1911_f_. An attempt to analyze the constitution of the chromosomes on
the basis of sex-linked inheritance in _Drosophila_. Jour. Exp. Zool.,
11, p. 365, Nov. 1911.

1912a. Eight factors that show sex-linked inheritance in _Drosophila_.
Science, Mar. 22, 1912.

1912c. Heredity of body-color in _Drosophila_. Jour. Exp. Zool., 13, p.
27, July 1912.

1912d. The masking of a Mendelian result by the influence of the
environment. Proc. Soc. Exp. Zool. and Med., 9, p. 73.

1912e. The explanation of a new sex-ratio in _Drosophila_. Science, 36,
p. 718, No. 22, 1912.

1912_f_. Further experiments with mutations in eye-color of
_Drosophila_. Jour. Acad. Nat. Sci. Phil., Nov. 1912.

1912_g_. A modification of the sex-ratio and of other ratios through
linkage. Z. f. ind. Abs. u. Veterb. 1912.

1914a. Another case of multiple allelomorphs in _Drosophila_. Biol.
Bull. 26, p. 231, Apr. 1914.

1914b. Two sex-linked lethal factors in _Drosophila_ and their
influence on the sex-ratio. Jour. Exp. Zool., 17, p. 81, July 1914.

1914c. A third sex-linked lethal factor in _Drosophila_. Jour. Exp.
Zool., 17, p. 315, Oct. 1914.

1914d. Sex-limited and sex-linked inheritance. Am. Nat., 48, P. 577,
Oct. 1914.

1915a. The infertility of rudimentary-winged females of _Drosophila_.
Am. Nat., 49, p. 40, Apr. 1915.

1915b. The role of the environment in the realization of a sex-linked
Mendelian character in _Drosophila_. Am. Nat., 49, p. 385, July 1915.

{86}

MORGAN, T. H., and C. B. BRIDGES.

1913. Dilution effects and bicolorism in certain eye-colors of
_Drosophila_. Jour. Exp. Zool., 15, p. 429, Nov. 1913.

MORGAN, T. H., and ELETH CATTELL.

1912. Data for the study of sex-linked inheritance in _Drosophila_.
Jour. Exp. Zool., July, 1912.

1913. Additional data for the study of sex-linked inheritance in
_Drosophila_. Jour. Exp. Zool., Jan. 1913.

MORGAN, T. H., and H. PLOUGH.

1915. The appearance of known mutations in other mutant stocks. Am.
Nat., 49, p. 318, May 1915.

MORGAN, STURTEVANT, MULLER, and BRIDGES. The mechanism of Mendelian heredity. Henry Holt & Co., 1915.

MORGAN, T. H., and S. C. TICE.

1914. The influence of the environment on the size of the expected
classes. Biol. Bull., 26, p. 213, Apr. 1914.

RAWLS, ELIZABETH.

1913. Sex-ratios in _Drosophila ampelophila_. Biol. Bull. 24, p. 115,
Jan. 1913.

SAFIR, S. R.

1913. A new eye-color mutation in _Drosophila_ and its mode of
inheritance. Biol. Bull. 25, p. 47, June 1913.

STARK, M. B.

1915. The occurrence of lethal factors in inbred and wild stocks of
DROSOPHILA. Jour. Exp. Zool., 19, p. 531-538. Nov. 1915.

STURTEVANT, A. H.

1913. The linear arrangement of six sex-linked factors in _Drosophila_
as shown by their mode of association. Jour. Exp. Zool., Jan. 1913.

1915. The behavior of the chromosomes as studied through linkage. Z. f.
Ind. Abs. u. Vereb. 1915.

TICE, S. C.

1914. A new sex-linked character in _Drosophila_. Biol. Bull., Apr.,
1914.

WHITING, P. W.

1913. Viability and coupling in _Drosophila_. Am. Nat., 47, p. 508,
Aug. 1913.

* * * * *

DESCRIPTIONS OF PLATES.

PLATE I.

FIG. 1. Normal [female].

FIG. 2. Sable [female].

FIG. 3. Lemon [male].

FIG. 4. Abnormal abdomen [female].

FIG. 5. Abnormal abdomen [female].

FIG. 6. Yellow [female].

PLATE II.

FIG. 7. Eosin, miniature, black [male].

FIG. 8. Eosin, miniature, black [female].

FIG. 9. Cherry.

FIG. 10. Vermilion.

FIG. 11. White.

FIG. 12. Bar (from above).

FIG. 13. Bar (from side).

FIG. 14. Spot [female] (abdomen from above).

FIG. 15. Spot [female] (abdomen from side).

FIG. 16. Spot [male] (abdomen from above).

FIG. 17. Spot [male] (abdomen from side).

* * * * *

Notes

[1] For a fuller discussion see "The Mechanism of Mendelian Heredity" by Morgan, Sturtevant, Muller, and Bridges. Henry Holt & Co., 1915.

[2] _B. C._ here and throughout stands for back-cross.

[3] The first dark body-color mutation "black" (see plate II, figs. 7, 8) had appeared much earlier (Morgan 1911_b_, 1912_c_). It is an autosomal character, a member of the second group of linked gens. Still another dark mutant, "ebony," had also appeared, which was found to be a member of the third group of gens.

[4] Wherever reference numbers are given, these denote the pages in the note-books of Bridges upon which the original entries for each culture are to be found.

[5] In addition to these expected F_1 wild-type females there occurred 13 females of an eye-color like that of the mutant pink. So far as was seen none of the F_1 males differed in eye-color from the expected eosin vermilion. Since the eosin vermilion and sable stocks were unrelated and neither was known to contain a "pink" as an impurity, these "pinks" must be due to mutation of an unusual kind. That these "pinks" were really products of the cross is proven by the result of crossing one of them to one of her eosin vermilion brothers, for she showed herself to be heterozygous for eosin, vermilion, and sable.

_F_1 "pink" (Ref. 51 C) [female] x F_1 eosin vermilion [male]._

+------+---------------+----------------+---------------+---------------+
| | Wild-type. |Eosin vermilion.| Eosin. | Vermilion. |
|Refer-+-------+-------+--------+-------+--------+------+--------+------+
|ence. |[female]|[male]|[female]|[male] |[female]|[male]|[female]|[male]|
+------+-------+------+---------+-------+--------+------+--------+------+
|59 C | 59 | 38 | 43 | 40 | 15 | 9 | 16 | 17 |
+------+-------+------+---------+-------+--------+------+--------+------+

In addition to the combinations of eosin and vermilion, sable also appeared in its proper distribution though no counts were made. The four smaller classes are cross-overs between eosin and vermilion. Since no "pinks" appeared the color is recessive, and the brother was not heterozygous for it.

Two other "pink" females mated to wild males gave similar results in their sons.

_F_1 "pink" [female] x wild [male]._

+------------+---------+---------+---------+-------+---------+
| | | | Eosin | | |
| |Wild-type|Wild-type|Vermilion| Eosin |Vermilion|
| Reference. |[female].| [male]. | [male]. |[male].| [male]. |
+------------+---------+---------+---------+-------+---------+
| 61 C | 101 | 33 | 37 | 9 | 11 |
+------------+---------+---------+---------+-------+---------+

These F_1 flies should all be heterozygous for "pink." A pair of wild-type flies which were mated gave a 3 : 1 ratio--wild type 51 to "pink" 18. From the "pinks" which appeared in this cross a stock was made which was lost through sterility. Females tested to males of true pink were also sterile, so that no solution can be given of the case.

[6] Purple is an eye-color whose gen is in the second chromosome.

[7] The curve published by Miss Stark included by mistake 6 cultures from the succeeding generations, and these coming from only one of the lethals (lethal _sb_) increase its mode so that the mode of the other lethal (lethal _sa_) becomes submerged. If these cultures are taken out the curve shows two modes more clearly.

[8] The figures to the left in each double column correspond to the symbols above the heavy line, as, in the first example 6,219 white miniature. The similar figure to the right corresponds to the symbol below the heavy line. If no symbols are present below, as in the first example, the column to the right should be read wild-type.

* * * * *

Changes made against printed original.

Page 24. "two contrary classes, eosin vermilion and bar": 'eosin bar and vermilion' in original.

Page 59. "The bristles which are most distorted": 'disorted' in original.

Pages 69-70. One or more lines are missing before "5,352".

Ibid. "The data just given in table 51": 'table 50' in original.

Page 75. "lethal 3_a_ lies at about 19.5.": 'lethal 3' in original.

Page 77. Table 58, last "Facet": 'Fecet' in original.

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