356 ADELE M. FIELDE. 



which they emerged, remaining for many months without visi- 

 ble growth, and then developing simultaneously with the issue 

 of eggs deposited a half year later. I am informed by Dr. J. 

 H. McGregor that larvae of Camponotus americamts have re- 

 mained such during ten months in his artificial nests at Columbia 

 University ; and by Dr. I. A. Field that larvae of Camponotus 

 pcnnsylvanicus remained under his observation in apparent good 

 health and without visible growth for nearly fifteen months. 

 Admitting that certain eggs were deposited by workers, we still 

 lack assurance that introduced larvae were not mingled with their 

 issue, and thus there is created a reasonable doubt as to the 

 origin of the callows appearing in the nest at a later date. 



To a third category we may relegate the numerous accounts, 

 including my own, concerning the offspring of workers that had 

 previously lived with males, and also those accounts in which 

 male ants were hatched and permitted to remain within the 

 segregated group of workers. We know that ants sometimes 

 mate within the nest, and we have the results of many dissections 

 indicating the capacity of certain workers for impregnation. 

 Miss Holliday ' found not only ovaries but a seminal receptacle 

 in certain individuals representing three genera of ponerine, two 

 genera of myrmicine, and one species of camponotine workers, 

 none of whom was externally distinguishable from its fellows. 

 We can no longer consider the workers of all species of ants as 

 sterile females. In view of the evidence that among workers, 

 showing no difference in external structure there have been found, 

 in numerous species, many members with both ovaries and semi- 

 nal receptacles ; and of the testimony of competent witnesses 

 that the male ants sometimes pursue the workers with an ardor 

 equal to that shown in their pursuit of the queens, we must 

 abandon the long cherished notion that eggs deposited by worker 

 ants are always unimpregnated. 



We do not know even that ant-eggs may not be fecundated 

 outside the body of the female, and this possibility should not be 

 ignored in cases where the egg-piles are traversed by mature 

 males in pursuit of queens and workers. 



1 "A Study of some Ergatogynic Ants," Margaret Holliday. Contribution from 

 the Zoological Laboratory of the University of Texas, June, 1902. 



