Bearers of Hereditary Characiers 207 



fined, chaos rather than cosmos would have resulted. 

 Actually we know that cosmos exists, and our highly 

 theoretical scheme at least can account for that. After 

 all, what is this scheme but the "intracellular pangene- 

 sis" of De Vries (see chapter xiv) ? 



Applying the scheme still further, we may make two 

 assumptions: (i) certain unusual physiological con- 

 ditions are capable of "releasing" determiner-enzymes 

 earlier than they would naturally be released. Thus 

 they are free to react in an unusual medium, or to inter- 

 act with other determiner-enzymes which they would 

 not have met in the natural course of events. In 

 either event the reaction is an unusual one, and the 

 final result may be the appearance of an unusual plant 

 character. (2) Unusual physiological conditions may 

 per se bring about unusual reactions and result in 

 unusual plant characters. The determiner-enzymes 

 would not be involved in this. 



These two possibiUties would account for some of the 

 unusual (hereditary) responses that have appeared as 

 the result of unusual physiological conditions, as, for 

 example, the mutants obtained by Macdougal (2) when 

 he injected the ovaries of Onagra with various chemicals. 

 In short, such a theory may help to reconcile some of the 

 apparently contradictory data of the physiological school 

 and the cytological school. 



To apply this theory to the matter of sex determina- 

 tion would involve certain difficulties, since sex is a 

 unique character and is inherited in a unique way. It 

 is quite possible, however, to overcome these theoretical 

 difficulties and to make our scheme reconcile the two con- 

 flicting views even on the matter of sex determination; 



