FORMICA. 299 



together, but subsequently the nest went wrong, and they both 

 died on the same day 66 . 



In 1911, 1912, and 1913 I tried numerous similar experiments, all 

 of which were failures, for although the strange females generally 

 become friendly, resting side by side and cleaning each other, etc., 

 and often living together for months, before *any results were 

 obtained one or the other has died. 



On July 3rd, 1913, Crawley found a sanguinea-fusca colony 

 (situated in a tree-stump at Weybridge) consisting of an equal 

 number of workers and cocoons of both species, the sanguined all 

 being small. He took as many of the pupae as he could obtain, 

 which subsequently hatched and produced thirty-five sanguinea 

 workers and thirty-four fusca workers. The situation of the nest 

 prevented him from digging it up properly to ascertain if a fusca 

 queen was present as well as a sanguinea^. 



On May 1st, 1914, Pinkney discovered a small colony at Woking 

 (situated in a bank) which consisted of a sanguinea queen, sixty to 

 eighty very small sanguinea workers, and three fusca workers 84 . 

 The six cases mentioned above are, as far as I am aware, all the 

 incipient colonies of F. sanguinea that have been recorded in 

 Europe. 



In 1910 Wasmann enumerated the following six ways in which 

 he suggests fertile sanguinea females may found their colonies : 



1. With the help of workers of their own colony : by branch 

 nests. 



2. With the help of workers of a strange colony of their own 

 species : by the adoption of the female into a strange colony. 



3. With the help of grown-up workers of the auxiliary species : 

 by the adoption of the sanguinea female into independent 

 colonies of fusca or rufibarbis. 



4. With the help of worker pupae taken by force from the 

 auxiliary species : colony-founding by a pupa raid. 



5. With the help of pupae of the auxiliary species, which 

 sanguinea workers had left behind when plundering a slave- 

 nest : colony-founding with pupae found. [After a slave raid 

 at Lippspringe which Wasmann observed on July 21st, 1909, he 

 found a number of fusca pupae left behind which the sanguinea 

 workers had either forgotten or intended to come back for, and 

 in any case he suggests a sanguinea female wandering about after 

 the marriage flight might easily have discovered them and 

 appropriated them to bring up her brood when hatched. This is 

 quite feasible, for when I introduced fusca pupae to some of my 

 isolated sanguinea females they sometimes collected them and 

 rested on the top.] 



6. With the help of females of the auxiliary species, when a 

 sanguinea and a fusca, or rufibarbis, female find themselves 



