168 Mr. Poulton's notes in 1885 upon 



what must be a common observation, that ichneumons 

 and dipterous parasites often emerge at the time when 

 we are expecting the lepidopterous imagos. Under such 

 circumstances the parasitic insects must live for a long 

 time before they can deposit their eggs, although it is 

 very likely that many of them do so when their victims 

 are comparatively young, but it is unlikely that such is 

 the case with this species. 



I am now able (May 25th) to add to the proof-sheets 

 of the paper an account of the time of pupation in this 

 species. In the first week of May (1886) the seven larvae 

 began to change in shape owing to the development of 

 the pupa beneath the skin, and the outlines of abdomen 

 and thorax were suggested. At this time each larva 

 expelled from the anus a relatively large amount of 

 faeces in the form of a long black nearly solid cord, 

 which was dilated at intervals. Newport states that the 

 anus does not exist when the larva is attached to the 

 egg-shell, but that it, together with the posterior section 

 of the intestine, is formed as soon as the larva becomes 

 free. I did not notice the discharge of faeces at any 

 time before May, and I do not think that it can have 

 taken place, for the larvae were never moved from the 

 chip-box in which they fed upon the D. vinula, and 

 afterwards spun their common cocoon. If any faeces 

 were discharged they must have been spun up in the 

 silk, but no traces of them can be discovered. It thus 

 appears most probable that fasces are only discharged 

 once in the whole period of larval life extending over 

 nine months. 



As the pupae developed the brownish eyes became 

 visible beneath the larval skin. Pupation took place on 

 the following dates : — May 17th, one ; May 21st, one ; 

 May 23rd, one ; May 24th, two ; May 25th, one. The 

 seventh larva was hardened in a solution of corrosive 

 sublimate for histological investigation. 



14. Additional note on the distribution of derived 



PLANT-PIGMENTS IN CERTAIN LARV^.. 111 a paper ill thc 



Proc. Koy. Soc. (No. 2B7, 1885, p. 269), I gave an 

 account of the way in which altered plant-pigments take 

 part in larval colouring. The evidence was chiefly 

 derived from an examination of the strongly-coloured 

 blood of many i)upae ; but some larvae were also investi- 

 gated, and it was found that the green ground colour of 



