l8O HORACE DONISTHORPE. 







it causes her to behave as would a fertilized one. I have subse- 

 quently found this to be the case in all such experiments with 

 Formica females. In the genus Acanthomyops, Crawley has re- 

 corded that the act of removing the wings from virgin iimbratns 

 females was far from arousing the instincts possessed by a ferti- 

 lized queen. In the above-mentioned experiment with a virgin 

 female of fuliginosus, however, the effect caused by removing the 

 wings was to make her act undoubtedly as would a fertilized queen. 



Donisthorpe ('17) continues the story of the virgin fulighiosus 

 female mentioned above. By April 22, 1916, her gaster had com- 

 menced to swell, and on May 25 she laid a few eggs. On June 9 

 a larger packet of eggs was present, held up in one mass by several 

 of the umbratus workers. On June 25 two larvae had hatched, the 

 eggs having taken over two months to develop. The eggs con- 

 tinued to hatch very slowly, and on November 28 some fifteen 

 small larvae were present. On January 28, 1917, ten medium- 

 sized larvae were counted, and the fuliginosus female was sur- 

 rounded by a number of the umbratus workers. 



Donisthorpe ('18) reports further concerning this fuliginosus 

 female. On May i, 1917, a fresh packet of eggs had been laid 

 and the gaster of the female was considerably swollen. On May 

 22 there were present over 200 umbratus workers, the fuliginosus 

 female, one packet of eggs, and 9 full-grown larvae. May 24 some 

 of the umbratus workers were covering the larvae with bits of 

 plaster, etc., to help them to spin their cocoons. Unfortunately 

 during the author's absence in June and July the nest was allowed 

 to get too dry, and on his return he found the eggs, larvae, and 

 pupae had disappeared, and most of the umbratus workers had 

 died. On August 18 a number of Acanthoniyops (Donisthorpca) 

 nigcr worker cocoons from Woking were introduced, and these 

 were collected by the few remaining umbratus workers. The 

 workers from the nigcr cocoons began to appear on August 26, and 

 by October 13 all had emerged and were surrounding the fuligi- 

 nosus queen. A number of fresh umbratus workers were brought 

 home from Weybridge on October 16 and a few at a time were 

 introduced into the nest to strengthen the colony. At first the 

 niger workers killed them, and this went on till November, when a 

 few were received. From then onwards four, five, and six um- 



