10.2 



ANTS. 



been impressed by very different aspects of the complicated phenomena 

 of polymorphism, and that each has emphasized the aspect which 

 seemed the most promising from the standpoint of the general evolu- 

 tionary theory he happened to be defending. Escherich ( 1906) has 

 recently called attention to two very different ways of envisaging the 

 problem ; one of these is physiological and ontogenic, the other etho- 

 logical and phylogenetic. As these furnish convenient captions under 

 which to continue the discussion of the subject, ] shall adopt them, and 

 conclude with a third, the psychological aspect, which is certainly of 

 sufficient importance to deserve consideration. 



While the ontogeny of nearly all animals is a repetition or repro- 

 duction of the parent, this is usually not the case in the social Hymen- 

 optera, since the majority of the fertilized eggs do not give rise to 



FIG. 63. Vestigial wings in worker ants. (Original.) A, Mynnica scabrinodis 

 van, with spatulate wing vestiges on mesothorax ; B, and C. Thoraces of two other 

 individuals from the same colony, showing a more vestigial development of the 

 wings ; D, Soldier of Cryplocenis aztecns with mesothoracic wing vestiges. 



queens but to more or less aberrant organisms, the workers. And as 

 these do not, as a rule, reproduce, the whole phenomenon is calcu- 

 lated to arouse the interest of both the physiologist and the embry- 

 ologist. The former, concentrating his attention on the reactions of 

 the animal to the stimuli proceeding from its environment, is inclined 

 to study its later stages as determined by the reactions to such stimuli, 

 without regard to any internal or hereditary predetermination or dis- 

 position, while the embryologist seeks out the earliest moment at which 

 the organism may be shown to deviate from the ontogenetic pattern 



