28 



Mr. Carrington stated he had just returned from the North, 

 and with reference to the variety radiata, St., of Spilosoma 

 lubricipeda, Esp., remarked that between i860 and 1870 this 

 particular variety only occurred in a timber-yard close to the 

 railway station at York ; he now found that when the station 

 was enlarged the timber-yard was taken by the railway, but 

 the variety still occurred in the neighbourhood, and that from 

 the larvse now taken in the various gardens throughout the 

 district, a fair proportion of the variety was bred ; this was 

 interesting as showing the establishment of certain types of 

 variation. 



Mr. R. Adkin read a paper: " The occasional abundance of 

 certain species of Lepidoptera." Some observations were 

 made on the paper printed in full at end of this Abstract. 

 Mr. Tugwell exhibited long series of Continental and British 

 Deilephila gain, Schiff., to illustrate the difference in size 

 between the two ; he expressed himself as clearly of opinion 

 that the English-fed galii were smaller than those from the 

 Continent ; this he attributed to the larva not feeding up so 

 well in this country, in addition, none of those he had bred pro- 

 duced ova ; and he had no doubt that when it occurred in this 

 country, it was from ova deposited by immigrants, and that the 

 imagines produced were so weakened by our climate, that they 

 could not reproduce their species ; he also referred to Anosia 

 plexippus^ L., and Colzas edusa, Fb., as other instances of im- 

 migration. Mr. South, referring to the remarks on Plusia 

 gamma, L., said he should think it was an onward movement ; 

 in that case not emigration, but immigration ; from the Isle of 

 Wight to the mainland, a continuance of the migration. 

 With regard to the whole question he was inclined to go a 

 very long way ; he thought that many generally distributed 

 species really became common in certain years, from the 

 fact that large numbers came over here and helped to 

 produce the abundance occasionally noticed. Referring en- 

 tirely to common species, he instanced Agrotis saiicia, Hb., as 

 being in many years quite scarce, and in other years extremely 

 abundant, not only as regards the southern portion of the 

 country, but even far north ; another species was Triphczna 

 pronuba, L., no doubt favourable years would increase its 

 numbers, but in addition he certainly thought that the 

 species was sometimes so extremely abundant, that it must 

 have received some help from immigration. Mr. C. G, 

 Barrett thought there was a little more direct evidence than 

 mentioned by Mr. Adkin, in particular he remembered that 

 in 1872 the first specimens of Vanessa antiopa, L., recorded, 



