876 EXPERIMENT STATION EECORD. 



the essential qualities of a " stayer," and tlie severity of the race-course test 

 as a selective agent. 



The author states that dark red striated muscle is correlated with a capacity 

 for long sustained muscular effort and that an excess of a pale fiber is corre- 

 lated vi^itli inability to respond to repeated stimulation. "The muscles in the 

 heavy breeds of horse appear to be exclusively of a pale red variety. The 

 Shire horse, even when thoroughly conditioned and fit. rapidly suffers from 

 muscle asphyxiation if made to gallop at his top pace, poor as it is, for a 

 short distance. . . . The physiological properties of the muscles of certain race 

 horses are sharply defined from those of others. . . . The gametic composition 

 of these individuals is in accordance with a Mendelian conception of alternative 

 imit characters." " The graduated series of distances over which races are 

 run in Great Britain and Ireland provides a test which, though perhaps not 

 entirely free from error, is, nevertheless, a reliable standard by which an 

 individual horse's racing stamina can be assessed." 



Tables are presented to show that mares are at a disadvantage as race 

 horses after 2 years of age. 



A note on yellow dun horses and the relation of this color to chestnut, 

 C. J. Davies (Mendel Jour., 1912, No. 3, pp. 197, 198). — Some evidence is pre- 

 sented which throws doubt on the recessiveness of chestnut and other colors. 

 It is also pointed out that until some distinction is made between bay and 

 brown it will be impossible to analyze results on the inheritance of color in 

 horses. 



The horse's foot, E. T. Robbins (Breeder's Gas., 62 (1912), No. 8, pp. 305, 

 306, figs. 4). — A discussion of the essential points of the hoofs to be noted in 

 buying horses, based on many years' exi:)erience of an expert buyer. 



Laying test with different breeds of poultry, C. B. Jones ( Univ. Col. Wales, 

 Agr. Dept. Bui. 1 [1912], pp. 17-19). — ^An egg-laying test is reported which 

 lasted from December 1, 1908, to March 18. 1909. The 10 Plymouth Roclv hens 

 laid 237 eggs, the 10 Buff Orpingtons 491, and the 9 Partridge Wyaudottes 508. 



Egg-laying' competitions, D. S. Thompson (Dcpt. Agr. N. 8. Wales, Farmers' 

 Bill. 57, 1912, pp. IJf). — A summary of 10 years' worli at the Hawkesbury Agri- 

 cultural College and Exi>eriment Farm, Richmond, New South Wales. The 

 average number of eggs laid per hen was 131 in the first year's contest and 184 

 in the last year. There was also a noticeable improvement in the type of bird. 



Sex-limited inheritance in poultry, C. B. Davenport (Jour. Expt. Zool., 13 

 (1912), No. 1, pp. 1-18, pis. 8, fig. 1). — A brief review of previous investiga- 

 tions, and a complete report of work previously noted (E. S. R., 26, p. 878) in 

 support of the formula that sex-limited characters have their determiners in 

 the sex chromosomes. 



Reciprocal crosses were made with brown Leghorns and dark Brahmas. In 

 the Fi crosses all males were light, but the females differed accoi'ding as the 

 brown Leghorns or the dark Brahmas were used as the father. In the F- gen- 

 eration there were 2 kinds of males. The observations seem in accord with the 

 hypothesis that the male carries 2 sex chromosomes and the female 1, and that 

 the determiners for certain secondary sex characters are centered in the sex 

 chi'omosomes. although the development of other characters seems to be espe- 

 cially influenced or modified by the secretions of the sex glands. 



Study in ostrich breeding, J. L. Fbateuh (Bui. Agr. Congo Beige, 2 (1911), 

 Nos. 3, pp. 371-388; Jj, pp. G78-692; 3 (1012), Nos. 2, pp. 366-390; 3, pp. 719-739. 

 figs. 57; abs. in Internat. Inst. Agr. [Ro7ne], Bui. Bur. Agr. Intel, and Plant 

 Diseases, 3 (1912), No. 3, pp. 7Jf7-7Jf9). — A statistical and general article on 

 ostrich breeding in various countries. Methods of breeding and feeding are 

 described. 



