466 EXPEEIMENT STATION EECOED. 



"The secondary sexual characters of all male hybrids vs-ere normally de- 

 veloped. The wild C. rufescens has a smaller litter average than the guinea 

 pig. When the wild males were bred to guinea pig females, the size of the 

 litters was that of the guinea pig. The female hybrids produced by this cross, 

 however, gave a litter average intermediate between that of the wild and tame. 

 By repeatedly crossing the hybrid females of one generation back to guinea 

 pig males to produce the next hybrid generation, the litter average was raised 

 almost to that of the guinea pig itself. This is all the more interesting since 

 guinea pig males were used to raise the litter average. Two female hybrids 

 showed some male secondary sexual characters. One of these with marked 

 male instincts had abnormal ovaries. Abnormal ovaries were common in the 

 female hybrids. The sex ratio in the hybrids showed a marked preponderance 

 of females, especially in the early hybrid generations, i. e., in those generations 

 which must have been most hybrid in constitution." 



A bibliograpliy of references is included. 



Crossbreeding experiments with Himalaya and black X tan rabbits, V. 

 Haeckeb {Mitt. Naturf. Gesell. Halle, 2 (1912), pp. 21-24). — An account of 

 crossbreeding experiments with rabbits in a study of color inheritance. 



Babbit crossing, II, V. Haeckeb and Olga Kuttneb {Ztsclu: Induktive 

 Abstain, u. Tererbungslehre, 14 (1915), No. 2, pp. .'f9-70, pis. S, fig. i).— This is 

 a continuation of the work noted above. 



The inheritance of black-eyed white spotting in mice, C. C. Little (Amer. 

 Nat, 49 (1915), No. 588, pp. 727-740, figs. S).— The investigations Indicated that 

 spotting in mice is dependent upon more than one pair of clear-cut mendelizing 

 factors. Modifying factors which may be more or less difficult to analyze but 

 which nevertheless are certainly present contribute to the extent of variation 

 in spotted races. " Spotting in rodents Is tempting as genetic material because 

 of the clear patterns and contrast between colored and white areas. It is, 

 however, as a character extremely sensitive to minute quantitative and quali- 

 tative changes, and its apparent genetic simplicity is a snare and a delusion." 



The zoological relationship between the banteng (Bibos sondaicus) and 

 the zebu (Bos indicus), H. Cans (Kiihn Arch., 6 (1915), pt. 1, pp. 93-152, pis. 

 5). — This reports studies made of banteng and zebu skeletons with a view to 

 determining their physiological relationship. It is stated that there are three 

 possibilities: (1) The banteng is the primary type from which the zebu has 

 risen, the intermediate forms being dead or at least unknown; (2) the zebu Is 

 a cross between Bos primigcnius and the banteng; and (3) the banteng, zebu, 

 and B. primigenius have all sprung from the same primary type. The author 

 considers the last hypothesis as being the most probable. 



Wliat is a breed? O. Lloyd-Jones (Jour. Heredity, 6 (1915), No. 12, pp. 531- 

 537, figs. 4). — It Is pointed out that the definition of the word "breed" varies 

 with each kind of like stock, and Is based almost wholly on the arbitrary de- 

 cision of breeders. Various examples are given to demonstrate the truth of 

 this statement. When a group of animals becomes sufficiently set off to be 

 called by common consent a breed, a number of breeders unite themselves into 

 an association. The breed Is then definitely delimited, and from this time, but 

 not before, can the term pure-bred be correctly and safely applied to individual 

 specimens. 



A new feeding stuff, by-product of household garbage (Flour, Hay, Grain, 

 and Feed, 28 (1915), No. 1, pp. 30, SI). — The method of manufacturing a by- 

 product of household garbage for use as a feeding stuff Is described. 



Ricinus poisoning, Robert (Landic. Vers. Stat., 85 (1914), No. S-4, pp. 176- 

 191; abs. in Jour. Bd. Agr. [London], 22 (1915), No. 4, pp. 359-361).— A dis- 

 cussion on poisoning by the seed of the castor oil plant. 



