42 Annals Entomological Society of America [Vol.1, 



and in the temporary and permanent parasitism of certain ants, 

 are too obviously secondary and of too recent a development to 

 require extensive comment. The bond which held mother and 

 daughters together as a community was from the first no other 

 than that which binds human societies together — the bond of 

 hunger and affection. The daughter insects in the primitive 

 colony became dependent organisms as a result of two factors: 

 inadequate nourishment and the ability to pupate very prema- 

 turely. But this very ability entailed an incompleteness of 

 imaginal structure and instincts, which in turn must have con- 

 firmed the division of labor and thus tended to perfect the social 

 organization. 



Before further discussing the problems suggested by this view 

 of the origin of the colony and the general subject of polymorphism 

 it will be advisable to pass in review the series of different phases 

 known to occur among ants. This review will be facilitated by 

 consulting the accompanying diagram , in which I have endeavored 

 to arrange the various phases so as to bring out their morphologi- 

 cal relations to one another. The phases may be divided into 

 two main groups, the normal and the pathological. In the dia- 

 gram the names of the latter are printed in italics. The normal 

 phases may be again divided into primary or typical, and second- 

 ary or atypical, the former comprising only the three original 

 phases, male, female, and worker, the latter the remaining phases, 

 which, however, are far from having the same status or frequency. 

 The three typical phases are placed at the angles of an isosceles 

 triangle, the excess developments being place to the right, the 

 defect developments to the left, of a vertical line passing through 

 the middle of the diagram. The arrows indicate the directions 

 of the affinities of the secondary phases and suggest that those on 

 the sides of the triangle are annectant, whereas those which ra- 

 diate outward from its angles represent the new departures with 

 excess and defect characters. 



(i) The male (aner) is far and away the most stable of the 

 three typical phases which are found in all but a few monotypic 

 and parasitic genera of ants. This is best shown in the general 

 uniformity of structure and coloration which characterize this 

 sex in genera whose female forms (w^orkers and queens) are widely 

 different; e. g., in such a series as Myrmecia, Odontomachus, 

 Cryptocerus, Formica, Pheidole, etc. In all of these genera 

 the males are very similar, at least superficially, whereas the 



