I09 



was followed by the laying of fertile eggs. The explanation 

 was not obvious. 



Hon. W. Rothschild remarked that in those parts of the 

 range where the Pharmacophagus model was devoid of white, 

 the poly tes mimetic females were also devoid of white. 



Hon. N. C. Rothschild asked Prof. Punnett if Mr. Fryer 

 meant by sterility that no eggs were laid or that those deposited 

 were unfertile. 



A. Bacot said that in the case of fleas, by careful adjustment of 

 conditions, they had been able to obtain 80 per cent, to 100 per 

 cent, of fertile ova from Ceratophyllus fasciatus and Xenopsylla 

 cheopis ; but so far had not been able to get a higher percentage 

 than fifty to seventy of fertile ova from Pulex irritans. This could 

 only be attributable to difference in feeding. Whilst the two 

 rat fleas had unlimited opportunities for feeding, the P. irritans, 

 owing to lack of time, did not get more than fifteen minutes daily 

 to imbibe. 



E. B. PouLTON then communicated a paper by Mr. C. F. M. 

 swynnerton ou : 



Pellets Ejected by Insect-eating Birds after a Meal of 



Butterflies ; 



and exhibited the pellets referred to, together with set examples 

 of the butterflies named. 



In the pellets of birds fed on Lepidoptera the remains of these 

 insects were only to be found by minute microscopical search 

 (cf. Vol. II., p. 351). 



R. Newstead asked if Prof. Poulton could state what 

 was the period between the taking of food and the casting of the 

 pellet in insectivorous birds. He added that, in his experience, 

 he had not found the remains of butterflies amongst the food 

 contents of British birds, though an abundance of many other 

 groups of the Insecta was discoverable. He called attention to 

 the fact that swallows, the Butcher Bird, Lanius excnbitor, and 

 Larus ridibundiis all cast pellets in the same manner as the 

 hawks and owls. 



A. Seitz bemerkte, dass es erwiesen sei, dass Vögel Tagfalter 



