270 EXPEEIMENT STATION RECOED. 



the problem of the heredity of color, with a discussion of the Bunsow, Struwe, 

 Crampe, and Walther theories on color inheritance and of the relation of these 

 to the principles of Mendelian inheritance. Part 4 treats of hereditary diseases, 

 including periodic ophthalmia, cribbing, roaring, and foal lameness. 



The author's observations led to the conclusion that a pathologic fold of the 

 eyelids is hereditary, especially in the maternal line. Periodic ophthalmia was 

 found to be hereditary in some cases, and not in others. Roaring was proved 

 to be hereditary. Spavin, navicular disease, and broken windedness were not 

 transmitted ; however, it is thought that the first 2 diseases can be transmitted 

 by animals that are much affected by them. 



Breeding and raising horses for the United States Army, M. F. De Baene- 

 VXLLE (Jour. U. S. Cavalry Assoc, 24 (WIS), No. 99, pp. 411-415).— A general 

 account of the horse-breeding and training operations in use at the Front Royal 

 Remount Depot, Va., and at other remount depots. 



How to buy a horse, C. W. Gay and D. S. Miller (Perm. Live Stock SarHt. 

 Bd. Girc. 24, pp. 9). — This circular briefly treats of the general principles to be 

 observed in selecting and buying a horse. 



The Shetland pony, C. and Anne Douglas {Edinburgh and London, 1913, 

 pp. XI-}-176, pis. 25). — ^A very complete volume treating of the early history of 

 the Shetland pony, present day types, and the care and management of this 

 breed. There is appended a detailed account, by J. C. Ewart, of the physio- 

 logical changes incident to the origin and development of ponies in general and 

 this breed in particular. 



The Grevy zebra as a domestic animal, G. M. Rommel (Anier. Breeders 

 Mag., 4 {1918), No. 3, pp. 129-139, figs. 5).— This is an account of the attempts 

 to cross the Grevy zebra on the common mare. In one case there was a 

 marked aversion on the part of the zebra, although no difficulty was experi- 

 enced in mating with a jennet. In another case there was less antipathy on 

 the part of the male zebra, but no mating resulted. Finally a number of 

 mares were artificially bred, with one live foal resulting. 



It was found that zebra semen does not contain relatively so many sperma- 

 tozoa as does that of the stallion, and this is thought to account in part for 

 the difficulty encountered in breeding by artificial means. It is noted that the 

 ass hybrids have no value as work animals, being decidedly donkey-like in dis- 

 position and habits. The mare hybrid is more like a horse in appearance and 

 manners. 



The author calls attention to the fact that the Grevy zebra is characterized 

 by its extreme quality or finish, which, if imparted in mule production would 

 offset any coarseness in the mares. It is susceptible to domestication and it is 

 thought that the size may be increased by feed and selection. With regard to 

 the effect of so-called telegony, or the influence of prior impregnation, it was 

 found that the mare which produced the zebra hybrid and afterwards was bred 

 to a Morgan stallion, produced a foal showing no evidences of the zebra im- 

 pregnation. 



Contrary to the usual manner of ass-mare hybrids, the zebra-ass hybrids, both 

 male and female, show sexual activity. They have been bred together, but with- 

 out results. Evidently the relationship between the zebra and common ass 

 is closer than that between the ass and horse. It is thought that the Grevy 

 zebra would prove of value as a farm animal, if properly handled. 



The call of the hen, or the science of the selection and breeding of poultry, 

 W. HoGAN (Petaluma, Gal., 1913, pp. 126, figs. 56). — The author outlines a 

 method for ascertaining the value of a hen by the relative thickness of and 

 distance apart of the pelvic bones. Tests for the determination of capacity, 

 condition, stamina, prepotency, and laying ability are described. 



