6 
owns to starving them a good deal. These were also fed on white¬ 
thorn. The result was 16 cocoons, every one of them dark. Wishing 
to see whether the species would bear forcing, on November 24th 1 
put three of my pale cocoons on damp sand in the forcing cage, which 
is kept in the kitchen, and on looking into it about three days later I 
was surprised to find that they had all turned dark brown. However, 
wishing to make quite sure, on January 1st I put three more with 
them, and on taking them out two hours later I found that the change 
had already taken place. 
“ I think that it would be as well here to summarise the histories 
of the two broods: —Bkood No. 1 (Mr. Bell’s): Larvae kept in a 
practically air-tight cage with damp atmosphere. Badly fed. Result— 
16 cocoons all dark. Brood No. 2 (my own) : Larvae well-fed and 
kept in a dry cage with plenty of light and air. Result—19 
cocoons, one only being dark. On six of the pale ones coming into 
contact with damp they turned dark almost immediately. 
“ With regard to the one dark cocoon, it seems to me that it is quite 
possible that in changing the food-plant I might have splashed it on 
pulling the old stalks out of the water-bottle, which would account 
for its colour. From the remarks of other lepidopterists that I have 
heard and read on the subject, I gather that the general idea is that 
the colouring matter is obtained from the alimentary canal, and is 
evacuated from the intestine and mouth by the larva on the interior 
of the cocoon, and also that the colour is not regulated by its environ¬ 
ment. Can it be that this substance is merely a sort of ‘ cement ’ to 
strengthen the cocoon and make it waterproof; depending on the 
dampness of the matter and the atmosphere for its colour ? From this 
it would seem that my larva*, through hereditary weakness, were 
unable to produce this ‘ cement,’ and being kept in a dry situation 
the cocoons remained pale. I think that it is the more likely, from 
the fact that the cocoons are somewhat thin in texture, and are not 
so hard as those that I have had before. 
“ I refrain from discussing the subject further, having had so little 
experience with the insect, but I should very much like to hear what 
others have to say on the matter.” 
Mr. Newbery stated that he had found the following plan very 
successful for relaxing Coleoptera :—First soak the specimen for 
twenty-four hours, or more, in water; then drain off superfluous 
moisture, and apply wood-naphtha with a brush till the specimen is 
sufficiently pliable to set. 
February 4th, 1896.—Exhibits :—Mr. Prout: a short series of 
Ili/dmecia hum s, from the Kyles of Bute. Mr. Bloomfield : a short 
but prettily marked series of Oporabia ililutata, bred from Ringwood 
pup*, and bearing some resemblance to (K Jilujranimuria. Mr. 
J. A. Clark : a beautiful series of Ay ruth tritiri from Howth (Ireland). 
Mr. Tutt remarked that the form with the pale costal streak seemed 
unusually prevalent in this locality, if the series exhibited was a 
typical one. Mr. Fuller : an old book entitled, “ A Collection of 
Curious Insects,” published by Laurie and Whittle, and dated 1794, 
though the series of 18 copper-plate engravings seemed older than 
that. Mr. Riches : living specimens of the slug, TcstairUa haliutidca 
