No. G2(\] 7.V XICOTIAXA TABACUM 229 



25% giant and many-leavod and few-leaved plants, 

 mutation arising as a hybrid. 



Honing (1914), in his studies of the aberrant types 

 occurring in Sumatra and Java tobacco, states that in 

 some instances 100 per cent, of the progeny of normal 

 plants were of the Mammoth type. According to Honing 

 even the Mammoth plants were not always constant in 

 their inheritance, and intermediate races were also 

 present. 



From Lodewijk's observations in Java, and the writer's 

 obser\^ations at Arlington Fann, Va., it is evident thai 

 intermediate races, as well as Mammoth t^-pes which 

 breed true, may appear in a progeny. Conceniing the 

 actual mode of origin of these intermediate and Mam- 

 moth races nothing definite is known. Hayes and Bein- 

 hart (1914), speaking of the origin of a Mammoth Cuban 

 type in Connecticut in 1912, say: 



This mutation must have taken place after fertilization, {. e., after 

 the union of the male and female reproductive cells. If the mutation 

 had taken place in either the male or female cell before fertilization, 

 the mutant would have been a first generation hybrid, and would have 

 given a variable progeny the following season. 



They assume that if one gamete alone were affected, a 

 progeny of hybrid character would have resulted, but if 

 we assume that one gamete can become so affected, it is 

 quite as reasonable to assume that both may sometime 

 be changed in the same manner. If such were the case, 

 ^Nfammotli ]ihnit< breeding true to this indeterminate 

 habit of growth would be expected. 



If, as Lodewijk finds, intermediate races behave as true 

 Mendelian hybrids, producing the theoretical ratio of 25 



