204 



JOHN L. PRICER. 



disappeared from sight. During the first eighteen minutes I 



counted only twenty-two ants, and then, as if by a sudden signal, 



the procession began to move, and during the following eighteen 



minutes I counted five hundred and twenty-two ants, and about 



this time the supply in the nest below seemed to be almost 



exhausted. A little before I stopped counting, large numbers of 



the larger workers began to arrive from the nest tree and to enter 



the temporary nest at the base of the tree. I have observed this 



colony repeatedly at different times during the night, and as late 



as two o'clock in the morning, and have always found them very 



active. 



Architecture and Economic Relations. 



McCook describes in detail the architecture of a colony of car- 

 penter ants which he found inhabiting a corner beam of an old 

 mill. ("A Guild of Carpenter Ants," Harper's Monthly, July, 

 1906.) In the same article he discusses serious injuries to for- 

 estry and lumber interest which have been reported to have 

 been done by the carpenter ants, and he also reports railroad 

 accidents which were thought to have been caused by carpenter 

 ants weakening the timbers of bridges. 



Dr. E. P. Felt, state entomologist of New York, also accuses 

 the large, black carpenter ants of doing much injury to forests. 

 ("Insects Affecting Forest Trees," Seventh Report, New York 

 State Commission of Forest, Fish and Game, p. 522.) In this 



Fig. 4. Two specimens of Xenodusa cava. 



article he shows in cuts the very different styles of architecture 

 followed by the ants in elm and in balsam and supposes that the 

 difference is due to the different structures of the two woods. 



The observations which I have made while collecting the 

 colonies represented in the tables of this paper lead me to believe 



