LUTHER BURBANK 



ganism showing a dominant quality does not carry 

 the opposite recessive factors dormant in its 

 germ-plasm. 



So far as we can judge, there is no limit to 

 the number of generations through which the fac- 

 tors for a recessive quality may be conveyed in a 

 state of latency or impotence, and yet may become 

 active and make themselves manifest through a 

 chance mingling with germ-plasm conveying simi- 

 lar recessive factors in the same state of latency. 



If I correctly understand the matter, recessive 

 characters are characters that are relatively old 

 in the evolutionary sense, and dominant char- 

 acters are those that are relatively new. In each 

 and every case where antagonistic qualities are 

 matched against each other there is reason to 

 believe that the newer character will tend to mani- 

 fest the phenomena of dominance, and the older 

 character the phenomena of recessiveness. 1 



The entire Mendelian formula might be said 

 to express nature's receptiveness toward innova- 

 tion, on one hand, and her tendency to hold fast 

 to that which has been proved good, on the other 

 hand. 



An organism that has acquired a new char- 



1 Perhaps it should be explained that this interpretation of the 

 underlying nature of the phenomena of dominance and recessive- 

 ness is original with the writer. It is based on a rather wide 

 study of the phenomena of Mendelian heredity in both vegetable 

 and animal worlds. It exactly reverses the explanation that has 

 been suggested by some other biologists, but the writer believes 

 that it is the most plausible interpretation of the phenomena in 

 question hitherto suggested. The basis for this belief will be else- 

 where set forth in detail. 



[314] 



