1917J ANIMAL PRODUCTION. 771 



Horse breeding and horse racing-, J. C. Ewart {Nature [London'\, 99 (1911), 

 No. 24S7, pp. 346, 347). — The author points out the necessity for the preserva- 

 tion of the Thoroughbred horse and for the improvement of the breed for mili- 

 tary and other purposes. As race horse breeding implies racing, the plea is 

 made for the continuance of such racing as may be required to test the value 

 of the stallions and mares now at stud in the United Kingdom. 



A history of the Percheron horse, compiled by A. H. Sanders and W. DiNS- 

 MOBE {Chicago: Sanders Publishing Co., 1917, pp. 602, pis. 131, figs. 10). — In this 

 history of the origin, evolution, development, and distribution of the modern 

 heavy draft type of Percheron horses the effort has been made to throw new 

 light upon the foundation history of the type in the district of the Perche in 

 France. Data for this part of the work were obtained from books, records, 

 and documents in the Government archives at Paris, including the official 

 registration and inspection entries of stallions bought for the French Govern- 

 ment stud at Le Pin, and lists of stallions approved and subsidized by the 

 Government prior to the Stud Book in tlie Perche. The evidence thus obtained 

 tends to show that the Percheron horse has existed as a distinct type from 

 very ancient times, and that Arabian blood has played very little part in the 

 production of the latter-day type of the breed. 



A detailed account is given of the introduction and dissemination of the 

 breed throughout the United States, to which is appended a symposium re- 

 flecting the views of contemporary importers and breeders on the selection, 

 feeding, and general management of stallions, brood mares, and foals. 



The diastatic action of saliva in the horse, R. J. Seymoxjb (Amer. Jour. 

 Physiol., 43 {1917): No. 4, pp. 577-585 ) .—Both the mixed and the isolated secre- 

 tions of the parotid and submaxillary glands of the horse were found to con- 

 tain a diastase capable of converting starch into sugar. The diastase is in- 

 dicated as being extremely feeble, requiring at least five hours for the conver- 

 sion of boiled starch. The action of the diastase (pytalin?) was not increased 

 by aeration, by acidifying, or by exposing to the action of weak alkalies. 



The saliva of the horse was found to be inactive on cellulose and on sucrose. 

 No evidence of the secretion of a zymogen with a subsequent conversion into 

 active ptyalin was observed. " Salivary secretion may occur in the horse with- 

 out mastication by stimulation with chemical substances, with an apparent aug- 

 mentation through the psychic effect of the sight of food ; the greatest flow oc- 

 curs when the horse is permitted to masticate food material." Potassium sul- 

 phocyanid was not found in the saliva. 



See also previous notes by Palmer (E. S. R.. 36, p. 82) and by Palmer and 

 others (E. S. R., 37, p. 681). 



Sex-linked inheritance of spangling- in poultry, G. Lefevee {Ahs. in Anat. 

 Rec, 11 {1917), No. 6, pp. 4^9 > 500). — A series of experiments has been carried 

 out at the Missouri Station for the purpose of determining the mode of in- 

 heritance of spangling in poultry (E. S. R., 35, p. 867). 



The initial crosses were made reciprocally between Silver Spangled Ham- 

 burgs and Brown Leghorns, and the material used for the analysis has been 

 obtained from twelve different matings. The conclusion has been reached 

 that spangling is determined in inheritance by a distinct factor which behaves 

 in a typically sex-linked fashion, the cocks being homozygous and the hens het- 

 erozygous for it in Silver Spangled Hamburgs. When spangling is introduced 

 through the male, both sexes in the Fj generation show spangles, while the 

 reciprocal cross gives only spangled males, the females being nonspangled and 

 incapable of transmitting the pattern. 



24656°— 18— No. 8 6 



