ANIMAL PEODUCTION. 671 



tissues and bone marrow. The renal and nervous tissues are free from the 

 stain, even when the fatty tissues are deeply colored. ^Muscle probably does 

 not take up the dye. It is seldom found in the liver, because the fat-soluble 

 dyes, which are insoluble in water, dissolve readily in the bile and are excreted 

 thereby into the intestine from which they can be reabsorbed. 



" The fat-soluble dyes may enter the organism from the alimentary tract 

 through the lymphatics, in solution in fat; or by the portal circulation, dis- 

 solved in reabsorbed bile. They do not pass beyond the liver unless fat is 

 present to transport them. Then they may be found in the blood, which is 

 rarely free from the dye in a normally fed animal that has once been stained. 

 A cycle between intestine, bile, and blood becomes established. No elimination 

 of the dyes occurs through the kidneys, except when an alimentary lipuria 

 arises (in rabbits and rats). 



" Contrary to the assertion of others, the stained fat is no less available to 

 the organism than the unstained. In cases conducive to fat transport — in 

 starvation, phosphorus and phlorhizin poisoning — stained fat migrates from 

 the stained depots to the blood and the liver cells. Here the dye is separated 

 and secreted into the bile, so that the liver, though having a high content of 

 fat, may be free from the dye. Stained fat does not traverse the placenta. 

 The blood of the fetus and the fat of young born of Sudan-stained mothers are 

 free from dye. 



" The excretion of Sudan III and Biebrich scarlet in milk, when they are 

 given with food fat, suggests that the latter may pass directly into the mam- 

 mary secretion. With cats and rats the results are striking, but the dye 

 excretion in milk ceases when the stained food is no longer fed. In guinea 

 pigs and goats the secretion of dye in the milk is positive; in the cow it haS 

 not yet been demonstrated. The variation in the outcome in the different 

 species may be due to variattous in the relative abundance in the dietaries of 

 fat necessary for the absorption and transport of the dye. This explanation 

 is emphasized by the observation that those animals (cats, rats, hens, pigeons) 

 for which fat enters more largely into the diet, become stained more easily or 

 speedily than animals which are accustomed to ingest relatively smaller amounts 

 of fat." 



The misuse of the term " melanin," R. A. Goetnee {Science, n. ser., 36 

 (1912), No. 915, pp, 52, 53).— The author suggests that we substitute for 

 melanin and melanin nitrogen of protein hydrolysis the terms proposed by 

 Osborne, humin or humin nitrogen, and reserve the term melanin for those 

 dark pigments which occur normally or pathologically in the animal body, 

 skin, hair, or feathers. 



The case of generalized melanosis in fowls, Lewin (Ztschr. Veterindrlc, 

 22 {1910), No. 10, pp. Ji55, 456; abs. in Berlin. Tierartsl. Wchmchr., 28 {1912), 

 No. 31, p. 567). — A brief description of a cock_in which melanotic pigment was 

 present in the muscles, bones, and other internal tissue as well as in epidermal 

 structures. 



The present status of the genetics problem, W. J. Spillman {Science, n. 

 ser., 35 {1912), No. 901, pp. 1 51-1 61 ) .—The author briefly discusses some of the 

 principal results which have been accomplished by the different methods of 

 studying heredity. Some suggestions for future work are offered. 



Negative results of in-and-in breeding among wild animals, W. T. Hoen- 

 ADAY {Proc. Intcniat. Zool. Cong., 1 {1901), pp. 162-16 Jf) .—The author believes 

 that the evil effects supposed to be due to in-and-in breeding when practiced 

 among domesticated animals do not occur in the case of wild animals, pro- 

 vided they are given free range, proper protection, and abundant food. These 



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