1906.] Wheeler, Founding of Colonies by Queen Ants. 49 



shape and arrangement of the chambers, the towelHng, sponge-slices, 

 roof-panes and the method of roofing the passage-ways between the 

 chambers, but for the glass floor and walls I have substituted a plaster 

 of Paris base and sides cast in a single piece. The dry plaster was 

 mixed with a pale reddish pigment and, after being cast and thoroughly 

 dried, was coated with varnish to prevent undue absorption of water 

 from the damp sponges. These nests are very easily made, are almost 

 as light and portable, and quite as satisfactory in all other respects as 

 the original Fielde nests. 



My simple experiments, which consisted in introducing female 

 ants into small colonies of workers of alien species, are open to 

 certain objections which may be briefly considered. Ex hypothesi 

 I should have used either incipient or depauperate, that is, very 

 small wild colonies of workers, and fertilized females that had just de- 

 scended from their nuptial flight, or had passed a few days roaming 

 about the country thereby ridding themselves of more or less of 

 their parental nest-odor. It may be contended, furthermore, that 

 the experiments should have been performed under conditions per- 

 mitting of the voluntary escape of females that failed of an amicable 

 reception among the alien workers. None of these conditions could 

 be realized for obvious reasons. Although young fertilized females 

 of the various species considered in this paper are occasionally seen 

 running over the ground just after the nuptial flight, one cannot rely 

 upon obtaining such specimens of a particular species when they are 

 wanted, and a systematic search for them would consume no end of 

 time and patience. Incipient and depauperate nests, too, become as 

 rare as hen's teeth as soon as one begins to search for those of a partic- 

 ular species. I was compelled, therefore, either to adhere rigidly to 

 the conditions implied in the hypothesis concerning the founding 

 of colonies by Formica species of the rufa, exsecta and sanguinea 

 groups, and plan the work for several summers after locating colonies 

 and studying the exact dates of the nuptial flights, or to use unfer- 

 tilized and artificially dealated females and small numbers of workers 

 taken from adult colonies of other species. I chose the latter course 

 and soon found that the results were very nearly the same as would in 

 all probability have been obtained by the former with its almost 

 insuperable difficulties. Contrary to what might be expected, the 

 act of fecundation has little effect on the subsequent instincts of the 

 females, and a small number of workers when isolated from a flourish- 

 ing colony, either through what may be called an awareness of lack of 

 backing by numbers, or for some other reason, are often as cowardly 

 [May, igo6.] 



