468 EXPEKIMENT STATION EECOKD. 



The nature of the inheritance of horns in sheep, T. R. Aekell and C. B. 

 Davenport (Science, n. set:, 35 (1912), No. 911, p. 927).— An explanatory note 

 concerning the work of Castle previously noted (E. S. R.. 27, p. 370). 



Is there association between the yellow and agouti factors in mice? A. H. 

 Sturtevant (Amer. Nat., 46 (1912), No. 5/f6, pp. 368-37 J).— Evidence is sub- 

 mitted to show that the ticking or the agouti factor is closely associated with 

 the factor which produces yellow-haired mice. 



Evidence of the zebra in the pleistocene fauna of i'rance, S. Trotter 

 (Science, n. Her., 33 (1911), No. 849, p. 530).— A study of the drawings in 

 L'Art pendant L'Age du Renne, by Edouard Piette (Paris, 1907), leads the 

 author to believe that the zebra lived in western Europe as a contemporary of 

 the cave bear, woolly rhinoceros, and other animals depicted by paleolithic man. 



Some current conceptions of the germ plasm, R. A. Harper (Science, n. 

 ser., 35 (1912), No. 911, pp. 909-923). — This is an address made before the 

 American Association for the Advancement of Science, 1911, and in which the 

 recent studies on fundamental problems of ceil behavior and heredity are 

 reviewed. The author finds that the later researches strengthen the view that 

 chromosomes are the bearers of hereditary traits, but that the attempt to ex- 

 pi-ess the results in terms of unit characters is but a relic of the earlier cor- 

 puscular and preformational theories of heredity. 



On melanin, R. A. Gortner (Biochem. Bui., 1 (1911), No. 2, pp. 207-215).— 

 A summary of work, wherein it is pointed out that the work of different in- 

 vestigators is not comparable because of the diversity of methods. The follow- 

 ing conclusions are drawn : 



"All available data indicate that the formation of melanin is brought about 

 by the interaction of an oxidase and an oxidizable chromogen. Melanins are of 

 at least 2 types, which may be differentiated by their solubility or insolubility 

 in dilute acids. Those melanins which are soluble in dilute acids are of a pro- 

 tein nature, and for this tyi>e the name melano-protein is suggested. It appears 

 probable that these melano-proteins are not present as granules, but that they 

 are ' dissolved ' in the keratin structure. The melanins which are insoluble in 

 dilute acids are of an unknown constitution, and are, probably, the ' pigment 

 granules' which may be seen in the hair and tissues. It is probable that 

 they are formed by the oxidation of a different chromogen from that which 

 yields the melano-proteins. The protein portion of the melano-protein molecule 

 is readily decomposed by the action of alkalis or acids; and colored products 

 are obtained which are not soluble in dilute acids. Tyrosin, lysin, and arginin 

 have been identified among the hydrolytic products of a melano-protein. So- 

 dium hydroxid solution decomposes the melanin molecule, and causes a loss of 

 both nitrogen and hydrogen. As many different products as may be desired 

 can be obtained by varying the strength of the alkali employed." 



The origin of the melanotic pigment in the embryonic eye and in malig- 

 nant tumors, A. von Szilly (Arch. Mikros. Anat., 77 (1911), No. 2, I, pp. 

 87-156, pis. 4; ahs. in Jour. Roy. Micros. Sac. [London], 1912, No. 2, pp. 168, 

 169). — The author studied the eyes of several vertebrate embryos and melanotic 

 tumors in the eye of man. The pigment bearers were found to arise from the 

 chromatin of the nucleus and pass into the cytoplasm, being comparable to 

 chromidia. Some are of a degenerative type, and their appearance is asso- 

 ciated with a partial breakdown of the nucleus. The change of colorless pig- 

 ment bearers into pigment is brought about by specific cell ferments, which 

 act on the chromatin. 



On melanin of animal origin, M. Piettbe (Compt. Rend. Acad. Sci. [Paris], 

 153 (1911), No. 17, pp. 782-785; abs. in Chem. Ztg., 35 (1911), No. lU, p. 



