21 



L. acervonim in a nest of 7^"". pratensis at Rannoch in June 1911, 

 and Crawley a deälated female of L. affino-tubcrum in the 

 earth of a nest of Tctramorium cœspitum in the New Forest in 

 July 1912. 



Our British species of Leptothorax are peaceable ants, and 

 do not appear actively to resent the intrusion of strange ants 

 of the same species. Donisthorpe placed two colonies, each 

 containing a queen and brood, from fir-stumps, some distance 

 apart at Weybridge, into the same plaster nest, where they 

 brought up their joint brood in perfect amity, and Crawley, 

 in July 1 91 2, united two colonies of L. aßno-iuberum from the 

 New Forest, and found that they placed their brood in a single 

 pile and mingled without any animosity. This being the case 

 with Leptothorax, there is every reason to suppose that deälated 

 females are received in strange nests after the marriage-flight. 



The enormous females of Tctramorium cœspitum are cer- 

 tainly capable of founding colonies unaided. In July 1906 

 Wasmann found a number of deälated females of this species 

 after the marriage-flight, near Luxembourg, some under stones 

 in little cells. He took seven females and put them with damp 

 earth in an observation nest, where they fought each other. 

 On September 4th there was only one female surviving, enclosed 

 in a cell with eggs and small larvie. 



The females of T. guiñéense, a species common in hot-houses 

 throughout the world, are very little larger than the workers. 

 Nothing appears to be known as to their habits of colony- founding. 

 Crawley observed a colony in a green-house at West Leake, 

 Notts, during 1908 and 1909, and found that the queens came 

 out of the nest and wandered about just like the workers, and 

 we both found them doing a similar thing at Kew Gardens in 

 1910. 



W. W. Smith (1892) found incipient colonies of T. uitidum 

 and striatum in New Zealand, under stones covering a network 

 of vegetation, on which numbers of aphides and coccids were 

 subsisting. These colonies ranged from a few ants of both 

 male and female sex up to fair-sized nests containing workers. 

 The ants were often seen carrying coccids about, and, from only 

 finding nests under stones where there were coccids and aphides. 

 Smith suggested that the females, after the marriage-flight, 



