PLANT BREEDING 555 
for constant intermediate hybrid races which I think has never before 
been mentioned. In crossing species of the genus Nicotiana, I have 
had plants develop from seed that have apparently been formed 
apogamously, that is, formed from an immature egg cell without fer- 
tilization. It is evident that this is induced by the extraordinary irri- 
tation of foreign pollen. The true hybrid plants that are formed are 
generally blends in the first generation. The question, then, arises : 
May not the difficulty of maturing sexual cells in a wide cross some- 
times cause apogamous development and therefore a continued propa- 
gation of a constant and uniform race? 
All but the last of these suggestions may also be pertinent in the 
case of varietal crosses where there is said to be a blending of char- 
acters that deal with size. I am not certain, however, that all the so- 
ealled blend hybrids might not show segregation if studied in large 
numbers. I have found such segregation in size characters in crosses of 
both maize varieties and of tobacco varieties.* 
®In the writer’s paper “The Role of Selection in Plant Breeding ” in the 
August number of this journal, the legends for figures three and four unfor- 
tunately were interchanged in printing. 
