1901.] NATURAL SCIENCES OF PHILADELPHIA. 541 



resident ants shows that the aura pervades the air or the ether, and 

 gives intimation of the presence of the intruder without denoting 

 her exact location. 



The aura of an ant of the same colony appears often to deter- 

 mine the route of a companion not within touch of the antennre, 

 when burdens are being carried into the nest. 



The distance to which the nest-aura is diffused may depend upon 

 the number and quality of the living inmates. 



Before an ant is five days old it has all its reflexes established, and 

 ai:)pears to have sprung as from the head of Jove, full grown and 

 completely accoutred, into active existence. 



Callows that became such in the T corner of the maze straightway 

 found a way into the nest, and commenced the carrying in of the 

 inert young. 



Callows less than five days old, that had never seen a queen, 

 nor adults, nor earth, were transferred from their Petri cell to a 

 handful of their ancestral soil, and they immediately built a nest 

 with runs and recesses such as are made by experienced workers of 

 their kind. 



Prolonged captivity in a glass house does not diminish their 

 ability to use earth in nest-making. I transferred to the earth 

 on a Lubbock nest, when they were nine months old, some queen - 

 less ants that had always lived without earth in one of my artificial 

 nests, and gave them a few larvse and pupse. Within ten hours 

 they had made as perfect runs and recesses as any ever constructed 

 by their species, and had disposed the young in the same manner 

 as do their free congeners. 



The unremitting attention habitually given by the workers to 

 the young is hardly demanded by the necessities of the latter. I 

 segregated eggs, larvpe and pupre, and found that eggs untouched 

 during several days bring forth normal larvre; that with no atten- 

 tion from the ants the full-grown ld,rva may successfully become a 

 pupa; and that the whole pupa-stage may be safely passed with 

 no more tending than such occasional changes of position as will 

 prevent the growth of raovdd. Penicillium Grustacemn^^ grows to 

 ripeness, in either darkness or light, upon eggs, larvre or pupa?, if 

 left for a few days unattended in the humid atmosphere required by 



" The moulds here mentioned were identified for me by Dr. George T. 

 ISIoore, of Dartmouth College. 



