416 WILLIAM MORTON WHEELER 



their foraging trips is some five times greater than in the 

 inferior genera {Messor, Tapinoma, Aphcunogaster, Monomorium) 

 and the various "trajets" and "tournoiements" are each over 

 a proportionally greater area. That the continual return, after 

 the detours of exploration, to the direction of the first sally 

 from the nest, as well as the podometric sense and the recogni- 

 tion of landmarks near the nest entrance all imply a kind of 

 memory is clearly admitted by Cornetz. 



Crawley ** describes the various ways in which ants greet 

 one another. The species of Myrmica merely touch one another 

 with their antennae. In the species of Formica this gesture 

 is often prolonged, especially in hot weather. These ants and 

 the species of Lashis and Camponotus also jerk the body forwards 

 in greeting. They do not, however, butt one another with 

 their heads, as is usually stated, but merely touch with the 

 antennae. These jerking movements of the head are not ex- 

 hibited by Myrmica and Tapinoma. " In case of alarm, ants 

 rush About the nest in great excitement, infecting every ant 

 they n:^eet with alarm, until the whole nest is aroused." Only 

 young queens respond to the salute of the workers; "an old 

 queen in a large nest never does." 



Crawley *' records some observations on a large colony of 

 Lasius fuliginosiis which, to his knowledge, had been nesting 

 partly in an old stump and partly in the beams of a house, for 

 ten years. The nest seems to have contained workers of L. 

 umbratus (at first incorrectly identified as L. flavus) , indicating, 

 as Lannoy has since shown, that L. fnligiiwsiis is a temporary 

 parasite on L. umbratus, which is in turn a temporary parasite 

 on L. niger. In the fuliginosus colony observed by Crawley 

 about one ant in eight carried a small commensal mite of the 

 genus Antennophorus. 



Crawley '" made several observations on the relations of the 

 little isopod Platyarthrus hoffmanseggi to various ants. He 

 found that most species are hostile and devour or drive away 

 these crustaceans, but that Lasius flavus and L. niger seem to 

 be very tolerant of them. As a rule "L. flavus receives Platy- 

 arthri from nests of its own species and from nests of L. niger 

 and others without taking any notice of them. These small 

 blind woodlice pass their whole existence in ants' nests, and 

 when about to moult or produce offspring, are found in small 



