{ xiv ) 



had been thrown on the observation by Col. Yerbury, who 

 pointed out that both flies were males. At first sight it 

 seemed astonishing that the bees should be pursued by the 

 males of inquiline flies ; but Professor Poulton suggested the 

 males in this way find their way to the burrows, where they 

 meet the females which have also reached them in the same 

 manner, or where more probably they lie in wait for the 

 freshly emerging females. 



The Ptev. A. E. Eaton doubted that the object of the male 

 flies following the bees was to be guided to whei'e the female 

 flies were likely to be found. He remarked that these Biptera 

 frequent the Andrena colonies and have no need to be guided 

 to thera. And might not these males have chased the bees 

 just as Va7iessidie and Ilesperiidx dart at and pursue any 

 Bomhus or Pieris that happens to fly past their resort? 



Professor Poulton considered that the cautious and per- 

 sistent tracking described by Mr. Hamm was inconsistent 

 with Mr. Eaton's suggestion.* 



Pa2Jers. 



Dr. G. B. LoNGSTAFF, M.D., read a paper " On some Bionomic 

 Points in certain South African Lamellicorns." 



Mr. Poland Trimen, F.R.S., communicated a paper " On 

 some new or hitherto unfigured species of South African 

 Butterflies." 



Commander J. J. Walker communicated a paper entitled 

 " Some Observations on the Eeproduction of Hemiptera- 

 Cryptocerata " by C. Goidon Hewett, B.Sc. 



* Since the meeting of the Society on February 7th, the two flies have 

 been further examined by Mr. J.E. Collin, who writes, Feb. 19tb, 1906 :— 

 " After a microscopical examination I consider tliem unJoubtedly/cwirtZes : 

 all Mr. Verrall's are females, but there is a male among the specimens in 

 his European collection from Kowarz." The two specimens had been 

 previously studied with the lens, but not the compound microscoite, by 

 Col. Yerbury, Mr. E. E. Austen, and Mr. Collin himself; and all thiee 

 Dipterists had then considered thenr to be males. It is fortunately 

 possible to correct the mistake on the very page in which it is printed. 

 The story enforces Darwin's conclusion that errors of fact are more 

 dangerous than errors of hypothesis. 



The eyes of these female Hies are of a size and relative position whicli 

 seem to imply the male sex. The eyes of male flics in general are 

 probably chiclly developed for the pursuit of the female, and it may well 

 be that they are similarly formed in these females in order to aid in the 

 pursuit of the Hymenopterous host. [E. B. P.] 



