36 



INHERITANCE IN GUINEA-PIGS. 



of matings), which has the same expectation of red-eyed young (50 per 

 cent), we get a total of 58 dark-eyed and 51 red-eyed, fairly good 

 agreement with the expected equality. 



By dark-eyed daughters which have produced red-eyed young and 

 so have shown that they transmit either red-eye or albinism, cf 1002 has 

 produced 18 dark-eyed and 16 red-eyed young; expected 25.5 and 8.5. 

 Doubtless other daughters which have not chanced to produce red-eyed 

 young in the litters recorded are also heterozygous for red-eye, in which 

 case their recorded litters should be added to the foregoing. If this 

 were done, the observed departure in this case from the expected 3 to 1 

 ratio would doubtless disappear. 



TABLE 22. Classification of young of &1002 by his granddaughters which were also his 



daughters (table 21). 



By pink-eyed daughters, d" 1002 has produced 7 pink-eyed young and 

 8 with eyes not pink complete agreement with the expected equality. 

 By daughters not pink-eyed, but which nevertheless are clearly hetero- 

 zygous in pink-eye, he has produced 23 pink-eyed and 58 not-pink-eyed 

 young; expected, 20 and 61 an excess of pinks capable of explanation 

 on the same ground as the excess of red-eyed young. 



By dilute-colored daughters 6^1002 has produced 52 dilute-colored 

 young, but no intense-colored ones, as expected, since dilution is 

 recessive to intensity. By intense-colored daughters heterozygous for 

 dilution he has produced 10 intense and 9 dilute young, equality being 

 expected. 



MISCELLANEOUS MATINGS OF THE DESCENDANTS OF d" 1002. 



Matings of the descendants of d" 1002 beyond the F 2 generation were 

 made chiefly with a view to test further the genetic character of the new 

 varieties. Their results are presented in tables 23 to 28 and serve to 

 confirm the interpretations already offered. 



