522 Journal of Comparative Neurology and Psychology. 



He demonstrated that ants enclosed in a wire gauze cylinder could be exposed 

 to an arc light, at a temperature of 40° C, for an hour without being injured. From 

 this he concludes that the nocturnal habits of this ant are the result not of necessity, 

 but of preference. This is a broader conclusion than the experiment seems to 

 warrant. 



McCooK and others have held that this ant has an architecture of its own, and 

 some have claimed that it damages trees and timber. The observations of Mr. 

 Pricer seem to show conclusively that it injures neither trees nor timber and that 

 it has no architecture of its own, but lives in the abandoned burrows of wood borers 

 and, unless the wood is rotten, it never alters the shape of these burrows. 



Five experiments upon instinct and intelligence led to the following conclusions: 



1. Ants are capable of tracking themselves and others of the colony; but they 

 are incapable of distinguishing the direction in which the trail was first laid down. 



2. Ants do not depend entirely upon following trails in finding their way about, 

 but are guided often by memory of the location of things and probably depend, as 

 a last resort, on a sense of direction. 



3. Ants ordinarily pay very little attention to trails when traveling from the nest. 

 In the main the above conclusions harmonize well with the results stated in my 



paper on the Homing of Ants.* 



He also claims that there is no evidence of anything akin to reason. 



From the standpoint of comparative psychology, probably the most interesting 

 portion of the paper is the record of the experiments on the power of communica- 

 tion. The author placed a number of larvae upon a small island which was con- 

 nected, by means of bridges, with the food chamber of the nest. An ant discov- 

 ered these and returned, empty handed, to the nest. There it butted against several 

 workers and then retraced its steps to the larvae. The ants thus saluted, and no 

 others, followed it. This was repeated several times with practically the same 

 result. Once, however, two out of eight ants saluted reached the larvae before 

 the ant that discovered them had retraced its steps that far. This most interesting 

 experiment led to the conclusion that ants can communicate. One cannot help 

 wishing that the author had devised an experiment which precluded the possibility 

 of the response being due to an odor conveyed by the ant from the discovered larvae 

 to the ants saluted. 



The following epitome of an unpublished experiment of mine upon an allied 

 species (C. herculeano-ligniperdus) will emphasize the importance of this precau- 

 tion. The colony, which was housed in a Janet nest, usually kept a guard in the 

 entrance. One day some strange ants (Formica fusca var. subsericea) forced their 

 way past the guard to some food which I had placed just inside the nest. The guard, 

 after fighting them for a while, retreated into the inner chamber, rushed about 

 among the ants and then returned to the fray, followed by several others. This 

 looked like communication. To test the matter the following experiment was 

 devised. I heated dissecting needles and glass stirring rods red-hot, to destroy 

 any odor, and, as soon as they were cool, fought the guard with them. Soon it 

 retreated into the inner chambers, rushed about among the ants and then returned, 

 alone, to the outer chamber. Then I dipped the needle or the stirring rod into oil 

 of cloves and again fought the guard. It again retreated to the inner chamber, 



* Turner, C. H. Jour, of Comp. Neur. and Psy., vol. 17, p. 423, 1907. 



