1918] ANIMAL PRODUCTION. 275 



tion of types and breeds. Disease and injuries are treated in part 2. A bib- 

 liography is appended. 



Selection of breeding- draft horses, C. N. Arnett {Montana Sta. Circ. 69 

 (1911), pp. 17-32, figs. 15). — This circular treats in a general way of the judg- 

 ing and selection of draft breeding stock. 



Distribution of public service stallions in V/i-sconsin in 1917, A. S. Alex- 

 AXDEE (Wisconsin Sta. Bui. 283 (1917), pp. 64, fiQS. 4)- — The total number of 

 pure-bred sires has fallen from 1,814 in 1916 to 1,723 in 1917, while stallions of 

 all kinds have fallen from a total of 3,062 in 1916 to 2,804 in 1917. However, 

 the percentage of pure-bred stallions has increased from 59.2 in 1916 to 61.5 

 in 1917. It is estimated that there were 715,000 horses in "Wisconsin January 1, 

 1917, with an average value of $120 each. 



A directory is given of the owners of public service stallions and jacks in the 

 State. 



The feminization of male birds, H. D. Goodale (Jour. Amer. Assoc. Instr. and 

 Invest. Poultry Hush., 3 (1917), No. 9, pp. 68, 69, 70). — An account of the suc- 

 cessful feminization of four cockerels by completely castrating and then im- 

 planting fresh ovarian tissue from related females. 



In the four cases it was noted that (1) the birds had the plumage of the 

 hen throughout, (2) the comb and wattles grew much more than those of the 

 capon and reached a size approximately that of the hen, (3) the spurs de- 

 veloped apparently nearly as much as in the normal male of corresponding 

 age, but as none of the living birds were sufficiently old no statement relative 

 to their continued growth with advancing years could be made, (4) the gen- 

 eral build of the birds was more like that of the cock than that of the hen, in 

 that they were rather coarse and rangey, but not more so than some individual 

 hens, and (5) one of the birds was quite masculine and two were practically 

 neutral in behavior. The fourth died before maturity. 



The condition of implanted tissue has been ascertained in two instances. 

 It was found that several pieces of the implanted tissues had been attached 

 at various places. In some the blood supply was well developed and some evi- 

 dence of increase in the size of the ova was noted, the largest reaching a size 

 of 3 mm. There has been no evidence, however, that the ova had exceeded this 

 size. 



Sex-linked inheritance of [spangling in poultry], E. H. Ruckee (-Jour. 

 Amer. Assoc. Instr. and Invest. Poultry Husb., 3 (1916), No. 1, pp. 6, 7). — Re- 

 sults are given of experiments which indicate that the factor of spangling in the 

 Silver Spangled Hamburg is sex-linked. However, the inheritance may be 

 modified by the presence of disturbing factors. 



In the experiments the initial crosses were made reciprocally between the 

 Silver Spangled Hamburg and the Brown Leghorn. The males derived from 

 reciprocal crossings were practically alike, having spangled bodies with black 

 tails, with the exception of four males which were entirely black. These black 

 cocks later gave the same breeding results as their spangled brothers. The 

 daughters of the reciprocal crosses were strikingly different. Those from Brown 

 Leghorn $ X Silver Spangled Hamburg ? were black with various degrees of 

 brown stippling on the wings, while those from Silver Spangled Hamburg $ X 

 Brown Leghorn $ had peculiar grayish feathers, showing crescentic penciling 

 with black and very distinct black spangles at the tip. The daughters then 

 inherited the spangling from the sire's side only. In the Fj generation all 

 crosses followed the sex-linked mode of inheritance. 



These results are in accordance with the hypothesis that in poultry the male 

 is homozygous for sex and the female heterozygous, and that the factors for 

 certain characteristics are linked with the factors for sex. 



