172 EXPERIMENT STATION EECORD. 



selection. Measurements were made of a large number of cross-bred horses and 

 comparisons made with those of pure-bred Belgians, showing the advantage of 

 using this breed in cross-breeding operations. 



Preliminary notes on the heredity of certain characters in a cross between 

 silky and Yokohama fowls, J. L. Konhote (Cairo Sci. Jour., '8 (1914), No. 91, 

 pp. 83-89). — "The object of these experiments, which have so far been carried 

 to the Fo generation, has been not only to study the inheritance of certain 

 definite characters but also to study the comparative inheritance of these char- 

 acters and to see if certain combinations would occur with greater frequency 

 than others. The silky male was dark-fleshed, white with short silky feathers, 

 a rose comb, five-toed, with feathered legs and a small crest. The Yokohama 

 female was white-fleshed, duckwing with long normal feathers, a single comb, 

 four-toed, clean legs, and no crest." The characters involved are discussed in 

 detail and it is shown how the expected Meudelian proportions with regard to 

 each character have been to a large extent realized. The author endeavors to 

 prove that " recessive characters will occur more frequently in females owing to 

 the absorption of more of their initial vigor on their sex, and so that recessive 

 characters more usually associated with the female can be produced in males 

 by an artificial reduction of vigor (cf. dun color in pigeons)." 



On the average the females have 0.41 more recessive characters than the 

 males, and the whites 0.74 more recessive characters than the colored. It is 

 suggested that " the proportions of Mendelian characters may be to a certain 

 extent governed by other causes, notably vigor, and that therefore from a prac- 

 tical point of view it becomes possible to increase the number of individuals 

 possessing a certain character by attention to such details as the food, temiiera- 

 ture, age of breeding stock, and time of year at which breeding takes place." 



Improving egg production by breeding, R. Peael (Maine Sta. Bui. 231 

 (1914), pp. 217-236, figs. 3). — This material has been previously reported (E. S. 

 R., 29, p. 874). 



Some factors influencing the bacterial content and keeping quality of eggs, 

 L. D. BusHNELL and O. Maueek (Kansas Sta. Bui. 201 (1914), pp. 749-777). — 

 The authors summarize the results of their studies, in which 2,759 eggs were 

 examined, as follows : 



"Almost all the eggs containing bacteria were infected in the yolk, while 

 very few of them showed bacteria in the white. Very few of the bacteria in 

 eggs grow at blood temperature, while they grow abundantly at room tem- 

 perature. This is of special interest because of its bearing on the hatching 

 quality of eggs. The number of infected eggs increases slightly with the age 

 of the fowl. Eggs from different hens vary widely in bacterial content and 

 keeping quality. The extremes for the whole period are percentage of eggs in- 

 fected — minimum 15, maximum 42 ; percentage of eggs spoiled — minimum 4, 

 maximum 34. The eggs from the same hens vary widely in bacterial content 

 and keeping quality at different times, and without apparent cause. When the 

 fowls were given range the number of infected eggs decreased. Feeding wet 

 mash produced an appreciable rise in the number of infected eggs. This in- 

 creased infection was due to bacteria growing at blood temperature. 



" Mating of the hens did not inci'ease infection of the eggs, as determined by 

 our methods. This suggests that the greatly increased spoilage of fertile eggs 

 is a direct or indirect consequence of the development of the embryo. Besides 

 giving rise to losses from blood rings, etc.. the presence of a dead embryo 

 seems to increase the susceptibility of the eggs to decomposition. "We have 

 observed frequent and striking divergencies between the number of eggs in- 

 fected and the number of eggs spoiled. Increase in infection and decrease in 



