106 GENETICS [Bot. Absts., Vol. IV. 



64S. Little, C. C. Colour inheritance in cats, with special reference to the colours black, 

 yellow and tortoise-shell. Jour. Genetics 8:279-290. Sept., 1919. — Author attempts to ex- 

 plain nature of sterile and fertile tortoise-shell males and anamalous occurrence of blacks. 

 Hypotheses of Ibsen, Wright, Doncaster, and Whiting are reviewed and criticized. Muta- 

 tion of yellow to black in parents accounts for anomalous black offspring. Tortoise-shell 

 males may result from non-disjunction, the sterile being "near males." — P. W. Whiting. 



649. Little, C. C. Human sex-ratio. Proe. Soc. Exp. Biol, and Med. 16: 127-130. 1919. 

 — From the records of the Sloane Lying-in Hospital, New York City, of 705S births, 5753 of 

 them progeny of pure racial matings of eight different European races, and 1305 progeny of 

 hybrid matings among these same races, author determined sex ratios and found a higher 

 percentage of males to females in hybrids than in pure stocks, 121.56 =*= 2.06 for hybrids, and 

 106.27 =*= 0.91 for pure stock. This is same result as that obtained by Pearl in 1908 using 

 data of Buenos Ayres including 219,516 births, though each ratio is higher than the corre- 

 sponding one in the South American data which gave a ratio of 105.99 = fc 0.39 for hybrids 

 and 102.21 * 0.16 for pure stock. Since Pearl's data did not take still-births into con- 

 sideration and it was not known what effect that might have on the result, Little tabulated 

 still-births separately, but found that their sex ratios are not significantly different from 

 those obtained for live-births or for all births together. He found also a lower percentage 

 of still-births in the hybrids than in the pure stock, 3.98 =*= 0.36 in hybrids and 6.17 =*= 0.21 

 in pure stock, indicating that hybrids in man tend to show the vigor characteristic of hybrids 

 in other animals. — Sylvia L. Parker. 



650. Little, C. C, and E. E. Jones. Inheritance of coat color in Great Danes. Jour. 

 Heredity 10: 309-320. Fig. 12. Oct., 1919.— The authors give a brief historical sketch of the 

 breed and a description of the color varieties. A review of previous literature follows in 

 which the behavior of color factors of other breeds is compared to instances occurring in Great 

 Danes. Assuming that Great Danes are a mixed population, characteristic ratios are given 

 for random matings using dilute and intense pigmentation. Observed experimental results 

 are based upon data derived from the American Kennel Club Stud Books, Volumes 11 to 34 

 inclusive. A detailed analysis of the inheritance of various color factors leads to the follow- 

 ing conclusions: (a) There is a single Mendelizing factorial difference between intense pig- 

 mented varieties and the dilute varieties. The factor for intensity being epistatic to its allelo- 

 morph, (b) The three coat conditions, black, brindle, and fawn are dependent upon three 

 mutually allelomorphic factors: E for full extension of black pigment, E' for partial extension 

 (the brindle pattern), and e' for its restriction to the muzzle, nose, and feet. The allelo- 

 morphs being E E, E E', or E e'; E' E', E' e'\ and e' e': (c) Harlequin spotting (H) is epi- 

 static to solid coat color (h); (d) The rare appearance of minute-white-spotted individuals 

 of a progeny of solid colored animals is probably due to a factor (s) which is hypostatic to its 

 allcmorph (.S') for self coat color. — Maxwell J. Dorsey. 



651. Loeb, Leo. The individuality-differential and its mode of inheritance. Amer. Nat. 

 54:55-60. Jan. -Feb., 1920. — Individuality-differential is a chemical characteristic which is 

 same for all tissues of one individual but different for different individuals. Inheritance of 

 differential has been tested in rats and guinea-pigs by transplantations from parents to chil- 

 dren, children to mother, and brothers to brothers. Differentials of children are intermediate 

 between those of parents, but very variable. Probably those of F 2 are also intermediate. 

 Author suggests that individual has two sets of differentials, one from each parent, and 

 each set consists of two kinds of differentials. Differentials are supposed to be related to 

 composition of chromosomes and to involve side-chains of proteins. — A. Franklin Shull. 



652. Lotsy, J. P. Mutatie of kruising, de oorzaak der evolutie? (Mutation from crossing 

 the cause of evolution?) Ncderl. Tydschr. Genceskunde 17 2 : 1395-1404. 191S. — In organic 

 matter form is always the result of a process of crystallization; per analogon to this in 

 organic beings also the form building results from a perpetual arrangement of the com- 

 posing parts according to their form. This analogon is allowed and defended with fol-. 



