94 MAINE AGRICULTURAL EXPERIMENT STATION. I9IO. 



of infertility obtained from either of the pure matings of the 

 two breeds entering into the cross during the same hatching 

 season. 



It seems unlikely that this considerable reduction in fertility 

 of eggs in the cross Cornish J' x Barred Rock 5 was due to 

 poor quality of the male birds used. The reason for this opinion 

 lies in the first instance in the fact that two different male Cor- 

 nish birds were used and both gave almost identical results. Both 

 were first rate specimens in all particulars so far as could be 

 told by external appearances. They were certainly vigorous 

 birds. This being the case it seems remarkable that both should 

 have shown so nearly the same degree of infertility of eggs. 

 On the other hand the result does not appear to be due to the 

 inclusion in the pen of a number of particularly bad individual 

 females that were incapable of making high fertility records. 

 AVhile in both halves of Table 4 there are individual females 

 with extremely poor records as to fertility of eggs, it is never- 

 theless the fact that the birds which gave bad results with one 

 of the cockerels are not the same ones that gave bad results 

 with the other, as would be expected to be the case if the fault 

 were primarily with the female birds. 



A suggestion which occurs to one in this connection is that 

 the Cornish Indian spermatozoa do not find the Barred Plymouth 

 Rock oviduct sO favorable an environment as they do the Cor- 

 nish Indian oviduct. It is a well known fact that in galli- 

 naceous birds the spermatozoa from one copulation fertilize a 

 number of eggs. In order that this may occur the spermatozoa 

 must live and remain in vigorous condition in the oviduct of the 

 female for a considerable period of time. In the present in- 

 stance there may be a lowering of the vitality of the Cornish 

 Indian spermatozoa due to a lack of adaptation to the con- 

 ditions presented by the Barred Rock oviduct. The significant 

 factors in such a case would probably be of a chemical character. 

 It is conceivable that the secretion of the Barred Rock oviduct 

 may be too acid or too alkaline to give the best results for the 

 Cornish Indian spermatozoa. Obviously the present data are 

 not sufficiently extensive to give any conclusive evidence in 

 regard to this suggestion. The great difference in the fertility 

 of eggs in the crosses made in the two different directions is, 

 however, of interest and deserves further investigation. 



