106 I May, 



traneous aid of absorbing media, can hardly be distinguished from 

 negatives taken on ordinary plates. If, however, a yellow glass be 

 interposed between the lens and the object photographed, there is a 

 distinct difference in resulting negatives, even when an ordinary plate 

 is used." 



The length of exposure is of course a matter of experience and 

 judgment. So much depends on the colours of the insects, the amount 

 of enlargement, and the actinic quality of the light. A point to be 

 remembered is that for each diameter the object is enlarged the exposure 

 must be increased accordingly. A full exposure is, as a rule, advisable, 

 and careful development to avoid harshness. 



Supposing the amount of enlargement obtained direct in the 

 apparatus is not considered sufficient, the film of the resulting negative 

 can be stripped from its support and remounted on a glass plate in a 

 much enlarged condition by the aid of the " Cresco-Fylma " Co.'s 

 enlarging solution. I find this process answers well in practice, and 

 the necessary density and sharpness does not seem to be reduced in 

 any way. 



To make enlargements of wings (showing the nervures) I use no 

 reflectors, but simply stick the wing on the plate glass (1), and having 

 put in the place of the cardboard (2) a sheet of ground glass, allow 

 daylight (or artificial) to shine through the semi-transparent background 

 and the wing. 



EXPLANATION OF PLATE IV. 



Top fig Wing of Chryso'ps coecutiens, L. 



Eight hand fig „ Ascia podagrioa, ¥ . 



Left hand fig „ Scatopse notaf a, Jj. 



Middle fig Crepidodera chloris, Foud. 



(Original length of C. chloris = m). 



Bottom fig Wing of Rhaphidia maculicollis, Staph. 



28, Elm Park Gardens, S.W. : 

 February, 1898. 



RESULTS OF PEOTEAOTED PUPAL CONDITION IN ASPS ALIA 



BIDENS. 



BT C. G. BARRETT, F.E.S. 



Some time in the autumn or winter of 1895 a friend sent me a 

 dozen or more pupae of this species in their neatly constructed cocoons 

 of silk and moss ; but the following spring brought something of dis- 

 appointment, since only two or three moths emerged, and these of the 



