DIMORPHIC QUEENS IN AN AMERICAN ANT. l6l 



" Not only is the normal occurrence of wingless females among 

 existing species evidence of a similar condition among the primi- 

 tive ants, but it also furnishes the most natural explanation of the 

 orio-in of the wingless workers. I surmise that the ancestral ants 



o o 



constituted small societies of wingless females, among which sterile 

 individuals were subsequently differentiated as ^vorkers. The 

 wings, so readily deciduous in the queens of existing ants, were 

 newly acquired from rudiments still persisting in the ontogeny, 

 by a process of reversion to the winged ancestors." 



\Ye are unable to assent to this view, for the following reasons : 



1. While there is no end of evidence to show that the most 

 diverse insects have lost their wings during phylogeny, there is 

 not, to our knowledge, a single insect which can be satisfactorily 

 shown to have reacquired these organs. At any rate the los- 

 ing of wings is a much easier process than their acquisition. 1 



Emery's hypothesis postulates a winged condition in both sexes 

 of the ancestors of Mutillid?e, a loss of the wings in the females 

 of the Multillid-like ancestors of ants, a persistence of this prim- 

 itive condition by inheritance in the ancestral Formicidae and a 

 comparatively recent reacquisition of wings in the females of all 

 except the Dorylinae and the few Ponerine genera which have wing- 

 less females (Leptogenys, Acanthostichus). This would seem to be 

 a needless complication of matters, apart from the fact that it is 

 venturesome to invoke the obscure principle of reversion to ac- 

 count for the reacquisition of organs. 



2. Existing wasps and bees certainly show the possibility of 

 differentition into workers and queens prior to the loss of wings. 



'This is an interesting case of a principle to which Headley ('01, pp. 100, 101) 

 has recently called attention : " The sudden loss of horns brings out a point to 

 which, I think, attention has never been directed in discussions on pammixis. The 

 evolution of new characters is a gradual process requiring ages of time. Geology 

 shows that the stag's antlers have grown step by ste*p from small beginnings. But 

 they might be completely lost in a single generation. The horns of cattle, though 

 less magnificent, are none the less the slow product of ages of unintermitted selec- 

 tion. But by a sudden freak they disappear utterly in an individual here and there, 

 or leave only a dangling vestige attached to the skin. 



" Those evolutionists who love symmetrical theories, mapped out regardless of 

 observed facts, imagine a process of retrogression by which all the stages are re- 

 traced in ordered succession. What actually happens is usually very different. An 

 elaborate organ is suddenly much reduced and mutilated or suddenly disappears alto- 

 gether." 



