No. i.] A STUDY OF SOME TEXAN PONERfNAE. 29 



of Ponerinae. The presence of a particular sexual phase is 

 indicated by a cross. 



Although it is by no means certain that the irregular poly- 

 morphism of the two sexes of the Ponerinae, as indicated in 

 this table, is due to an inability on the part of the ants to 

 regulate with precision the quality and quantity of the food 

 administered to the larvae, I nevertheless believe that there 

 is some causal connection between these two peculiar phenom- 

 ena. At any rate, we may assume this connection as a work- 

 ing hypothesis for future experimentation and observation. I 

 believe that continued study of the relatively undifferentiated 

 sexual conditions of the Ponerinae may lead us more rapidly to 

 a solution of the interesting problems of nutritional polymor- 

 phism than a study of the more specialized ants. 



When the larvae of the Ponerinae are mature they are, like 

 the mature larvae of the Formicinae, buried in the soil till they 

 have spun their cocoons. They are then unearthed and the 

 small adherent particles of soil are carefully removed by the 

 workers. I have watched the burying of the larvae in Lepto- 

 genys and the unearthing and cleansing of the cocoon in Odon- 

 tomachus. The cocoons of the three species of Ponerinae are 

 usually kept together, but the ants are scarcely as careful in 

 this respect as the species of Formica and Camponotus which I 

 have observed (F. ncontfibarbis and C. castancus). Nor do 

 they keep their larvae assorted according to sizes, a peculiarity 

 which accentuates the irregularity of their feeding habits. 



Forel, as we have seen, believes that Ponera coarctata 

 may escape from its cocoon without the assistance of the 

 workers. Unfortunately I had to leave my work at Austin 

 before the pupae of Odontomachus were ready to hatch, but I 

 am convinced that Leptogenys, at any rate, opens the cocoon 

 and draws out the pupa when ready to enter on its imaginal 

 life. I have not seen this operation under normal circum- 

 stances, as the two workers which appeared as callows in my 

 artificial nest left their cocoons when I was not present, but 

 for some reason the workers in this nest were continually 

 opening the cocoons near one end and pulling out the still 

 white pupae. Ten or a dozen workers would gather about 



