222 RAYMOND PEARL 



Cornish Indian Game matings 



The strain of Cornish Indian Game fowls used in these experi- 

 ments is characterized, as has already been pointed out, by very 

 poor egg production. There is no evidence that any of the individ- 

 uals, either male or female, ever carry the second fecundity fac- 

 tor Lo. These birds therefore represent the extreme condition 

 in the way of low fecundity as compared with the Barred Ply- 

 mouth Rocks. 



The Cornish Indian Game is an old breed and if one may judge 

 from poultrymen's accounts, there certainly have existed in the 

 past, and probably exist now strains of birds belonging to this 

 breed which are fairly good layers. Such strains, which are in 

 marked contrast to the one here used, undoubtedly carry, in 

 some combination, the second fecundity factor L2. There is 

 nothing extraordinary, or contradictory to the results of the pres- 

 ent paper, in such a fact (if it be a fact) . Indeed it will be shown, 

 in a later section of this paper, how it has been possible experi- 

 mentally to form synthetically high laying Game hens, i.e., to 

 put the factor L2 into their hereditary constitution (cf . section on 

 F2 matings). 



Owing to limitation of space and for other reasons it has not 

 been possible to carry on the fecundity studies with this breed on 

 anything like the same scale as with the Barred Rocks. There- 

 fore the numbers here dealt with will be smaller than in the 

 previous section. They will be sufficient, however, to indicate 

 clearly the hereditary constitution of the material. Of the possi- 

 ble types of C.I.G. d'd' in respect to fecundity as set forth in 

 table 7, two (class 2 and class 3) have actually been used in pure 

 Cornish matings (i.e., C.I.G. a" X C.I.G. 9). 



Matings of a Cornish Indian Game male of class 2 {table 7). 

 This d", no. 558, was hatched in the spring of 1908 and used to 

 head a pure Cornish pen in 1909. His breeding record indicated 

 that he was of class 2, with a constitution /Li?2 . fUh- His breed- 

 ing history was as follows: 



