182 



THE YOUNG NATUBALIST. 



5. Colias Edusa. — Nothing more to add. The immigration theory 

 appears to be gaining ground. 



6. Colias Hyalb. — The same remark may be made here. 



Mr. Decie is unable to understand how the fact that these two species only 

 retain their place by immigration helps my case, and asks for proof that they 

 ever were true natives. This, of course, I cannot supply, and they have both 

 been very erratic in their appearance for many years. Let Mr. Decie, how- 

 ever, explain why Colias edusa suddenly becomes abundant all over the island, 

 then gradually disappears, which occurs every few years, and if he can put 

 forward a better theory I will be glad to adopt it. If the spring immi- 

 grants produce the native born summer brood, why is the latter only able to 

 carry on its race to so limited an extent that a year or less sees the end 

 of it. 



7. Argynnis Paphia. — Mr. Clifford says it is much rarer in all parts of 

 England than formerly. I never saw it in this district, though it is on the 

 old lists for the county. 



8. Argynnis Aglaia. — Mr. Clifford seems to confirm my statement and 

 to imply that though formerly taken near Gravesend, it had already disappear- 

 ed when he commenced to collect 30 years ago. 



9. Argynnis Adippe. — Coupled with Aglaia in Mr. Clifford's remarks. 



10. Argynnis Lathonia. — Nothing has been advanced to controvert my 

 brief remark, but Mr. Clifford mentions the capture of twelve specimens one 

 season in a wood near Shoreham, as affording evidence that it may occasion- 

 ally breed here. Why it does not often do so is what needs explanation, 



11. Vanessa Polychloros. — Mr. Clifford names this species as being 

 "certainly less frequent than it was 20 or 30 years ago/' 



12. Vanessa. Io. — Mr. Clifford adds to my north country observation 

 that he has not seen it for many years in North Kent, where it was formerly 

 abundant. Mr. Pierce has only found one at Liverpool. 



13. Vanessa C-album. — Mr. Decie does not understand how any escape 

 the hop-picking in Herefordshire. I have had larvae from that county found 

 both on nettle and currant. It has gone from the hop districts of Kent. It 

 left Dorsetshire in 1816. 



14. Vanessa Cardtji. — I believe this species is much indebted to immi- 

 gration for its frequent abundance. It seems to disappear for years from 

 various places, sometimes it is not seen anywhere ; then a large flight reaches 

 us, it is common everywhere for a time, and again disappears. 



