LECTUKE XIV 



MONSTKOSITIES 



I have previously dealt with the question of 

 the hereditary tendencies that cause monstros- 

 ities. These tendencies are not always ident- 

 ical for the same anomaly. Two different 

 types may, generally, be distinguished. One of 

 them constitutes a poor variety, the other a rich 

 one. But this latter is abundant and the first 

 one is poor in instances of exactly the same con- 

 formation. Therefore the difference only lies 

 in the frequency of the anomaly, and not in its 

 visible features. In discovering an instance of 

 any anomaly it is therefore impossible to tell 

 whether it belongs to a poor or to a rich race. 

 This important question can only be answered 

 by direct sowing-experiments to determine the 

 degree of heredity. 



Monstrosities are often considered as acci- 

 dents, and rightfully so, at least as long as they 

 are considered from a morphological point of 

 view. Physiology of course excludes all acci- 

 dentality. And in our present case it shows 



400 



