THE TOMATO 173 



for a number of years before being placed under 

 conditions proper for its germination, might not 

 result in the production of a deformed or modi- 

 fied plant. 



Whatever differences of opinion may be held 

 among biologists as to the possible transmission 

 of modifications of the body plasm, all are 

 agreed that modifications of the germ plasm be- 

 come a permanent heritage and are passed on 

 to the offspring. So it seems at least a pos- 

 sibility that we have presented, in the deteriora- 

 tion of the germ plasm within the seed, an ex- 

 planation of the appearance of mutants or sports 

 that may become the progenitors of new races. 



Attempts to produce mutants by treating 

 the ovules of plants with chemicals, including 

 radium, have been made by several experimental 

 botanists, notably by Dr. D. T. MacDougal, of 

 the Desert Laboratory at Tucson, Arizona, and 

 by Prof. C. S. Gager. Prof. MacDougal's 

 evening primroses, grown from seeds that were 

 treated with chemicals while in embryo, some- 

 times differ markedly from other plants of the 

 species. 



Prof. T. H. Morgan has made similar experi- 

 ments with the eggs of a fly, treating them with 

 radium, and thus producing individuals strik- 

 ingly different from their parents. 



