( xxvili ) 
cent. of the larve could eat an entirely new plant was of great 
significance, and much helped to explain the changes which 
must have occurred during the spread of these insects into 
countries with a different flora. He also exhibited fourteen 
larve of Bourmia roboraria, of which seven had been sur- 
rounded by oak-leaves and green twigs, while the other seven 
had been surrounded by many brown twigs, in addition to 
the food; the latter became dark brown, but the former were 
without any exception much lighter. Mr. Poulton further 
exhibited some cocoons of Rumia crategata, the colours of 
which had been influenced by their surroundings. He 
observed that on a previous occasion, when he had exhibited 
the cocoons of Friogaster lanestris and of Halias prasinana, it 
had been remarked that the larve should be exposed to some 
permanent green colour during the construction of their 
cocoons, in order to test whether the same results would be 
produced as those which followed the presence of green 
leaves. The latter produced brown cocoons, and this result is 
protective, because the leaves turn brown, and so the cocoons 
are in contact with a surface with which they harmonize in 
colour; but of course the change in the colour of the leaf 
takes place long after the cocoon is constructed. Mr. Poulton 
had argued that the permanent green colour would produce 
‘the same effect as the leaves, if it affurded stimulus which 
sufficiently resembled that of the latter in character, while the 
converse supposition, that the larve spun the brown cocoons 
from choice, and because of their knowledge of the sub- 
sequent changes which the leaf would undergo (long after 
their pupation), seemed to him to be on the face of it utterly 
untenable. And so the cocoons of Rwnia crategata had 
proved it to be, for some of them were spun upon green paper, 
and these were (with one exception) light brown in colour, 
like those spun among leaves, while the cocoons spun against 
white muslin were quite white. 
Mr. M. Jacoby exhibited a varied series of Titubea sanguini- 
pennis, Lac., from Central America. He stated that many of 
the varieties exhibited had been described as distinct species. 
Mr. Billups exhibited specimens of Bracon brevicornis, 
Wesm., bred from larve of Kphestia hithniella. He remarked 
