COLOR 



59 



Not every one of these 32 varieties of gray rabbit has actually been 

 demonstrated to exist in the course of our experiments; 10, however, which 

 we have shown to exist, have already been mentioned, and several others 

 are known. For example, by crosses of black with pale yellow (cream) 

 or of blue with yellow, we have obtained grays which produced the same 

 sorts of young as variety 6, and in addition blue-grays, blues, creams, and 

 pale sooties. Such was the character of our gray females 1413, 1457, 1 5 2 5> 

 1526, and 2009. By a male of like character they have produced young 

 as shown in table 37. 



Other gray rabbits produced by the same crosses, black X cream, or 

 blue X yellow, produce the same assortment of young, and in addition 

 albinos. That is, they are like variety 8, but heterozygous in intensity of 

 pigmentation. These gray rabbits, females 1423, 1443, and 1505, and 

 males 1351 and 1458, mated inter se t have produced young as indicated in 

 table 38. . 



TABLE 38. 



The category yellow is probably too large because of a failure on our 

 part to discriminate between yellow and cream, a difference which at first 

 we failed to record. It is possible also that albion young were not enu- 

 merated in all the records which we have combined, and so albinos are 

 apparently deficient in number. 



It is needless to go farther in the enumeration of zygotic varieties of gray 

 rabbits. There is little doubt that the entire 32 varieties theoretically 

 possible could readily be produced; or we have found that a spotted 

 coat may be transferred from one color variety to another by means of 

 crosses, and the same is true of a dilute condition of the pigmentation in 

 contrast to intense pigmentation. It is known also from a variety of 

 sources, including besides our own observations the valuable experiments 

 of Hurst ( : 05) , that albinism may occur as a recessive character in any 

 and all color varieties of rabbits. Additional evidence seems to be desir- 

 able chiefly as concerns the assumed factor E; therefore, we may proceed 

 to the consideration of color varieties other than gray, in the course of 

 which this evidence will be produced. 



