May 16, 19()2.] 



SCIENCE. 



769 



ants begin to educate the fertile sexes, the 

 males and queens. Enormous numbers of 

 these, in some species hundreds or even 

 thousands, are produced during the most 

 favorable season of the year, and all these 

 individuals are carefully fed, groomed and 

 guarded by the workers till fully mature 

 and ready for the hymeneal flight. 



If v^e look upon the ant-colony as a com- 

 plex of more or less heterogeneous indi- 

 viduals, comparable to the Metazoan body, 

 which is also a complex of units, the more 

 or less differentiated cells, we may say that 

 the sexual individuals of the ant-colony 

 develop only under favorable trophic condi- 

 tions, just as the sexual organs of the Meta- 

 zoan mature only under similar conditions. 

 While this analogy is useful it is also 

 advantageous for present purposes to look 

 at the sexual forms of ants under a some- 

 what different aspect, viz., as organisms 

 that are educated to maturity in what is 

 essentially a state of domestication. This 

 is obvious when we consider that the males 

 and queens are not only reared from the 

 eggs, but fed, groomed and guarded by the 

 attendant workers throughout their whole 

 imaginal life in the nest. All these atten- 

 tions vividly recall the attentions lavished 

 by man on the animals of his household. 

 One is especially reminded of this resem- 

 blance on seeing the behavior of the work- 

 ers towards the sexual forms, just before 

 the latter are ready to take the nuptial 

 flight. The males and queens are permitted 

 on successive days to take the air about the 

 entrance of the nest. At such times they 

 are herded by the workers like so many 

 cattle, and hastily dragged or driven into 

 the nest on the slightest suspicion of dan- 

 ger.* The fostering instinct which, in the 

 ant colony, envelops both the mature forms 



* I have seen beautiful instances of this in the 

 Texan agricultural ant (Pogonomyrmex barbatus 

 Smith var. molifaciens Buckley) and in our 

 northern species of Lasius. 



and the young of all descriptions, consti- 

 tutes the basis from which myrmecophily 

 and the various forms of symbiosis in gen- 

 eral have been developed. The extraordi- 

 nary development of this fostering instinct 

 is demonstrated by the interesting fact that 

 no less than 1,500 species of Arthropoda 

 are now known to live with the different 

 species of ants on terms of amity or tolera- 

 tion. 



The sexual individuals, when finally 

 liberated from the nest, are thrown entirely 

 on their own resources, and for a time the 

 struggle for existence sets in with great 

 severity. One has an opportunity of 

 actually witnessing both catastrophic and 

 personal elimination often on a magnificent 

 scale. The struggle among the males for 

 the possession of the females is intense. 

 The lives even of the fortunate among the 

 former are rapidly extinguished. The sur- 

 viving, fecundated queens set to work to 

 establish their colonies, an arduous and 

 complicated undertaking which ruthlessly 

 eliminates all the poorly equipped. Even 

 before they can dig their nests hundreds of 

 these insects are devoured by birds, lizards, 

 spiders, etc. And many more of them die 

 from exhaustion while digging their nests, 

 or from hunger while raising their first 

 litter of young, or from the attacks of sub- 

 terranean predatory insects, parasitic 

 fungi, etc. This struggle, however, termin- 

 ates on the appearance of the first work- 

 ers, and the successful queens thenceforth 

 again lapse into a condition of domestica- 

 tion till the close of their often very long 

 lives. These general statements concern- 

 ing the formation and growth of the colony 

 wiU apply to most if not to all ants.* They 



* In a former paper ( ' The Habits of Ponera 

 and Stigmatomema,' Biol. Bull., Vol. II., No. 2, 

 Nov., 1900, p. 68) I maintained that the Ponerinae 

 perhaps constitute an exception to the general 

 method of establishing colonies, but I have re- 

 cently found in a small cavity in a stone a 

 fertile dealated queen of Odontomaohus clams 



