8988 Insects. 
which the central band is narrower than in English specimens, and 
altogether of one tint of rusty black, while the hind margin of the fore 
wings is much paler: the outer portion of the hind wings is also 
paler, but the line which runs across them is very much darker and 
more distinct: also two specimens from the Orkneys, in which the 
outer edges of the large band remain very dark and solid, while the 
central portion, especially near the costa, has become pale gray. It 
seems likely that very interesting varieties might be found in these 
islands. 
The difference in the habits of the two species is as follows: 
C. russata is double-brooded, the first brood appearing on the wing in 
May and June; and from the eggs deposited then the second brood 
appears in August and September: the eggs laid by this second brood 
hatch at once, and the larve attain the length of half an inch before 
they give over feeding for the winter; in February and March they 
feed up, and at the end of April are in pupa for the May moths. 
C. immanata has but one brood, which is on the wing in July and 
August; and although the eggs are deposited at once it seems they do 
not hatch till the spring. The great difficulty with them is that they 
so readily dry up; I have been disappointed in this way again and 
again, and Mr. Doubleday tells me that out of thousands of eggs which 
he has had at different times he never had one egg to produce a 
larva. 
Whether I shall be more successful this spring I do not know, but 
I have the following experiment in hand. On the 11th of August, last 
year, I took a female of C. russata; she began to lay at once in a pill- 
box, and her eggs hatched on the 23rd of the same month; the 
larve are now half an inch long, and after hybernation are just 
beginning to feed again. On the 12th of August I took a female of 
C. immanata var, marmorata; she also began to lay at once, and I 
managed to make her deposit some of her eggs on growing plants of 
wild strawberry (Fragaria vesca); and some she laid on the calico 
covering of the glass cylinder which enclosed her: both these batches 
I have kept out-doors ever since, taking care to shelter them in 
stormy or frosty weather, and up to this date those on the plant show 
no signs of shrivelling, whilst of those on the calico the greater part 
are quite dried up. It may be these eggs require a great deal of 
moisture to keep them from perishing, but why they should do so 
more than those of C. populata, C. dotata or C. prunata, which will 
hatch in spring after being kept for several months in a pill-box, 
I cannot explain. 
