372 EXPEEIMENT STATION RECORD. 



Scientific view of Barred Kock color standard, P. B. Hadley and J. H. 

 Robinson (Farm Poultry, 2}, (1913), No. 6, pp. 137, 138, fig. i).— This is a dis- 

 I'ussiou of the standard requirements in the barred plumage pattern in Barred 

 Plymouth Rocks, in which Robinson takes exception to Hadley's contention 

 that a standard requirement for barring pattern in the male and female birds 

 is impracticable due to a fundamental variation in the germ cells. The latter 

 contends that the male offspring is homozygous for the barring character, due 

 to a combination of these characters received from both its parents, but that 

 the female offspring is heterozygous, receiving its barring character from only 

 one parent, the male. Hence, since barring is an inhibiting factor for black, the 

 homozygous birds (males) are fundamentally lighter colored than the heterozy- 

 gous (females.). 



In order to prove that the female inherits barring from the father only, the 

 case is cited in which a Barred Plymouth Rock male was crossed on Rhode 

 Island Reil females, and vice versa. Barred progeny resulted in the first case, 

 but in the second case only the males were barred, since the females inherited 

 this character from neither father (Rhode Island Red) nor mother (Barred 

 Plymouth Rock). As against this is cited the case of experiments at the Cor- 

 nell Station in which White Leghorn males were crossed on Barred Plymouth 

 Rock females, producing barred females. Similar results in the personal ex- 

 perience of the author are also cited. 



This phenomenon is explained by Hadley as being due to the latent barring 

 character found in the White Leghorns which exerts itself when this cross is 

 made, providing the male is not pure for white. It is said that perhaps all 

 White Leghorns contain this barred character, the males being homozygous for 

 barring and the females heterozygous. 



Examples are given in which barred flocks have been built from a foundation 

 White Leghorn male. Evidently this male was not pure for white and the latent 

 barred character became evident. Had this White Leghorn male been pure 

 for white this character would have dominated over the black or barred 

 character. 



Hadley's general conclusion is that the homozygous condition of the male 

 and the heterozygous nature of the female with respect to this barring char- 

 acter prevents a remodeling of the standard regulations for the plumage of the 

 Barred Plymouth Rock breed. It is stated that further information is to follow 

 in a bulletin from the Rhode Island Station. 



Dig-estion in the chick, T. P. Shaw {Amer. Jour. Physiol.. 31 {1913), No. 7, 

 pp. Jf39-Ji.'i6). — This paper is a discussion of investigations upon the digestive 

 functions of the chick and of the physiological processes involved during diges- 

 tion. Two series of experiments were conducted: One, to determine the action 

 upon starch, protein, and fat of the digestive ferments fi'ora the tloor of the 

 mouth, crop, stomach, pancreas, and mucous membrane of the small intestine ; 

 the other, the action of the ferments upon the contents of the digestive tract. 

 Conclusions from these inve.stigations were as follows : 



" Extracts of the glandular structures of the floor of the mouth contain 

 amylolytic ferment active in an alkaline medium. This ferment was found in 

 extracts from a chick orue hour after hatching. The crop secretes no ferment. 

 The crop acts as a digestive organ by retaining the food for a considerable 

 time, thereby allowing the ptyalin in the saliva to act on the starch content. 

 By the second day the stomach of the chick secretes a gastric juice which con- 

 tains proteolytic and curdling ferments active in acid medium. 



" The pancreatic secretion in the chick contains proteolytic, amylolytic, and 

 lipolytic ferments which act best in a slightly alkaline nieilium. The fimc- 

 tions of the pancreas are imperfectly developed before the seventh day after 



