51 



same time. Mr. Adye also exhibited two examples of this 

 species, taken at Christchurch, Hants. 



Mr. Dennis exhibited a variety of Lycczna bellargtis, Rott., 

 the ground colour of the underside being whitish grey, and 

 all the spots, with the exception of those at the margins, 

 absent. 



Mr. PVohawk exhibited a branch or stem of alder with 

 pupa case of Sesia sphegiforntis, Fb., protruding therefrom, 

 and stated that the day before the imago emerged the pupa 

 broke through the bark, and remained protruding for a little 

 time in the sun ; it then drew back, and emerged the next 

 day (see also Mr. Tugwell's remarks, ante p. 39). 



Mr. Adye exhibited living larvae and pupae of Colias edusa, 

 Fb. ; and on behalf of Mr. McRae of Bournemouth, two 

 boxes containing examples of Colias edusa, Fb., van helice, 

 Hb., and C. hyale, L., which Mr. Adye said were a portion 

 of the result of five days collecting in the neighbourhood of 

 Bournemouth and Christchurch, Hants, by Mr. McRae, who 

 estimated the proportion oi helice to edusa females as one in 

 fifty, and of hyale to edusa as one in one hundred. 



The following extract from a letter from Mr. McRae as 

 to why C. edusa did not occur abundantly two years in suc- 

 cession, was read : — 



"Having observed that the ova of C. edusa are always 

 placed on the upper surface of clover blades, I am firmly of 

 opinion that cattle and sheep in grazing fields, and mowing 

 machines in hay-fields, are principal agents in the destruction 

 of the ova and larvae. An edusa year is doubtless due to an 

 exceptionally numerous immigration of the species, but the 

 destructive agents referred to play havoc with the offspring." 



Mr. R. Adkin pointed out that the larvae of C. edusa did 

 not always feed on clover, and unless it was confined to 

 cultivated clover he did not see how Mr. McRae's explana- 

 tion could be the right one ; although it might satisfactorily 

 explain a reduction in the numbers, it could not account for 

 the total extermination of the species for the second year. 

 Mr. Hawes thought it was necessary not to lose sight of the 

 fact that, so far as his observation went, the species flew 

 chiefly on railway embankments, and chalk downs ; and 

 bearing in mind the number of food plants besides clover, 

 upon which the larvae fed, he for his part could not see that 

 the prolongation of the species depended upon the cultivated 

 clover. Mr. Auld said that at Hastings he worked the clover 

 fields for some time, and got very few specimens, but found 

 them much more plentifully in the lanes and on the hills. 



