74 



THE YOUNG NATURALIST. 



[April 



suit his theory. We may therefore as well assume that the Cornish 

 specimens of ioth June had been out for a week or so, as to assume it 

 of the first recorded Deal specimen on 24th July. 



As regards parasites, Mr. Tugwell says, Galii are remarkably free 

 from them. Another Correspondent writes me, "that most of his larvae 

 (also from Deal) were ichneumoned, another instance of too hasty 

 generalization. 



As regards the size of the imagines, I think that if Mr. Tugwell 

 will but look over any quantity of bred continental galii, he will see 

 reason to modify his views. I must repeat that we cannot fairly draw 

 any inference from the comparison of the size of bred and captured 

 Sphingidoe. Bred specimens should for this purpose be compared with 

 bred specimens ; captured with captured. 



A few words more as to lying over. Mr. Tugwell asks "did any 

 one know a Deilephila pupa to remain two years in pupa? I never did." 

 I do not know what Mr. Tugwell's experience is with the other species 

 of Deilephila or with this in other years; but a correspondent informs 

 me that 1888, Galii pupae were still lying over,* which shows that here 

 again Mr. Tugwell is too hasty ; and I would also point out a fact 

 which Mr. Tugwell ignores, namely, that I was not then alluding to 

 Galii pupae in confinement which, as I believe was the case with Mr. 

 Tugwell's own, are usually forced. If I remember right Mr. Tugwell's 

 pupae even with forcing did not by any means emerge at one time 

 some lingered on in pupa. 



As for other Sphingidce lying over, it has been a matter of common 

 notoriety since Haworth's time: — He says of S. ligustri—" This very 

 fine species has been known to remain 2 and even 3 seasons in the 

 puppa state, and these become winged as perfectly and beautifully as 

 if nothing extraordinary had occurred." 



The same is the experience with this species of a friend of mine 

 who also noticed that the pupae on the surface or just below came out 

 the first year, those deeper the second year, and those deepest of all in 

 the third year. 



Facts like these should teach us that there are unknown and un- 

 suspected causes at work in nature, and should make us hesitate before 

 we dogmatize in our present scanty and superficial knowledge of her 

 mysteries. 



55, Lincoln Inn Fields, 25th March, 1890. 



* A Correspondent informed me, last week, that some of his galii were still lying 

 over. — March, 1890.— J. E. R. 



