Referate. 355 of these papers taken together are ( I ) t h a t in Birds sex-limitation is found in the female, while in Mammals it is in the male; and (2) that several new cases are described in which the coupling with sex is partial rather than absolute, L. D o n c a s t e r . Morgan , T. H. Heredity of Body Colour in Drosophila. Journ. Experim. Zooh I3. I. 1912. p. 27--46. (i colour plate.) Morgan, T. H., and Cattell, E. Data for the Study of sex-linkefl inheritance in Brosophi/a. Journ.

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... im. Zooh 13. i. 1912. p. 79--1o2. The first paper shows that the colour of /lie wild fly ("gray") is due to there factors, Black (B), Yellow (Y) and Brown (Br). Absence of B produces a yellow fly, absence of Y a black fly, absence of both B and Y, a brown. The factor B is sex-Iinked, but Y is not; whether Br is sexlinked has not yet been determined. It is pointed out that these factors for body-colour appear to correspond to the three factors for eye-colour already described, namely vermilion, pink, and orange, of which the pink and orange factors are sex-linked but the vermilion is not. These is however no organic correlation betweeu the body-and eye-colours, for any eyecolour may be associated with any body-colour. Some disturbances of the sex-ratio occur in the cro3ses with these colours, such as have been described in connexion with certain other mutations of Z)rasoSzik~, and the