1907.] Wheeler, The Polymorphism of Ants. 53 



of hunger and affection so beautifully described in the famous lines from 

 Schiller's " Die Weltweisen " : 



Einstweilen, bis den Ban der Welt 

 Philosophie zusammenhalt, 

 Erhalt sie [Natur] das Getriebe, 

 Durch Hunger und durch Liebe. 



The daughter insects in the primitive colony became dependent organisms 

 as a result of two factors : inadequate nourishment and the ability to pupate 

 very prematurely. But this very ability seems to have entailed an incom- 

 pleteness 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 diagram on 

 Plate VI, in which I have endeavored to arrange the various phases so as to 

 bring out their morphological relations to one another. The phases may 

 be divided into two main groups, the normal and the pathological. In the 

 diagram the names of the latter are printed in italics. The normal phases 

 may again be divided into primary or typical, and secondary or atypical, the 

 former comprising only the three original phases, male, female, and worker, 

 the latter the remaining phases, which, however, are far from all having the 

 same status or frequency. The three typical phases are placed at the angles 

 of an isosceles triangle, the excess developments being placed 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 tliose on the sides of the triangle are 

 annectant, whereas those which radiate outward from its angles represent 

 the new departures with excess and defect characters. 



1. The Typical, Atypical and Pathological Phases of Ants. 



(1) 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 colora- 

 tion which characterize this sex in genera whose female forms (workers and 

 queens) are widely different; e. g., in such a series of cases as Myrmecia^ 

 Odontomachus, Crypiocerus, Formica, Pheidole, etc. In all of these genera 

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

 females are very diverse. The body of the male ant is graceful in form, 

 one might almost say emaciated. Its sense-orgiins (especially the eyes and 

 antennae), wings and genitalia are highly developed; its mandibles are 



