568 Mygglfarolc Powell on the 
The spiracles are pale brownish discs set in slight depressions sur'- 
rounded by wrinkles. The segmental incisions are well marked. 
When active in this stage, that is to say after feeding has commenced 
and before the preparation for the second moult has suspended 
activity, the larva has a greyish-green tinge due to the presence of 
food in the alimentary organ. At other times the larva to the 
naked eye is of a pale coffee-brown colour. ‘The microscope breaks 
this up into paler, semi-transparent ground colour, and darker 
mottlings, and shows the dull white tubercles. The larva still feeds 
on the cuticle, not attacking the entire leaf substance. It draws 
together the edges of the leaf division in which it lives. 
On June 9 I left Hyeres for the Aisne Department, 
taking with me three larvae ina glass tube, two being in the 
2nd stage and one in the 38rd. Whilst away from Hyeres 
I fed these larvae on a common Potentil/a, forming close 
growing patches on sandy soil. It had a slightly hairy 
leaf. They took to it without any hesitation. (At 
Samoussy I noticed H. carthami frequenting patches of 
this Potentilla. ) 
Progress was very slow. On my return on July 1 the 
larvae were still in the same stages, though they had 
grown considerably. In changing their food I removed 
them each time from the tents they made with the leaves, 
and after cleaning the tubes replaced them with some 
fresh leaves. Kach one set to work at once to spin upa 
new tent, drawing together the edges of a division, or 
uniting two divisions to form a fairly roomy living-place. 
When moving, the larva spins silk continually. I believe 
it to have an aestivating habit. In captivity in a tube, 
where conditions were always moist, the torpid state was 
never fully developed, but progress became slow, and little 
eating was done. ‘The larvae nibbled bits out of the edges 
of the leaves of their tents. 
I had left the rest of the sidae larvae at Hyeres on 
growing plants of Potentilla hirta covered with muslin. 
Soon after leaving the eggs, those from ova laid in the 
flowers went down to the leaves. Here they progressed 
until the 3rd stage was reached in some cases, others 
not going farther than the 2nd stage. About that time 
the plants dried up from want of water. When I returned 
to Hyeres the plants were dry and brittle, and I was quite 
prepared to find the larvae dead. However, on opening up 
the dried leaf divisions, I found them looking comfortable 
