PC Es, 161 
At any rate the small Argynnids, as 
myrina and bellona, pass but four in sum- 
mer. Satyrus alope passes but four, 
although the only brood of the year is 
that of winter. In both these genera, the 
larvae eat nothing before lethargy, except 
their own egg shell, but feed for several 
days after awaking and before a molt 
comes on. 
The genera above mentioned, on which 
observations have been made, embrace a 
large proportion of those which belong 
to the North American butterfly fauna, 
and we may infer that butterflies of the 
other genera, at least those which inhabit 
temperate regions, will as a rule be found 
to behave likewise, and that the regular 
number of molts is four, except in cases 
of hibernation, three being a very rare 
exception. 
In the Entomologists’ Monthly Mag- 
azine for July 1880, Mr. Wm. Buckler, 
who has had very great experience in 
breeding lepidopterous larvae, contrib- 
utes a paper entitled: ‘+ Is the number of 
moults of lepidopterous larvae constant in 
the same species?” and begins thus: ‘‘ I 
have been impressed lately with the uncer- 
tainty that seems to exist as to the number 
of times lepidopterous larvae moult in 
course of their growth, and have been 
considering whence this uncertainty 
springs.... Or is it quite certain, as 
many think, that the number of moults 
varies in the same species’... I know 
that the number of moults certainly 
varies in different species. I have myself 
made sure that six is the number for 
some and nine for others, as in the case 
Nola centonalis.... Any one who has 
made notes.on which he can depend 
about the growth of any species he has 
reared, would I think do good service by 
publishing them,” etc. 
What I have said before will in some 
respects answer Mr. Buckler’s query, 
so far as concerns North American but- 
terflies at least. I have no doubt the 
several species are constant in the num- 
ber of their molts, the exceptional cases 
being as I have stated. 
But whether the same can be said of 
all species of heterocera I am not compe- 
tent to say. Certain observations made 
on Callosamia promethea would seem to 
indicate that there may be variability. 
I happened last spring to have a co- 
coon of this silk-worm moth, which I had 
brought in from a tulip tree, and as a 
female came from it, it occurred to 
me to see how many molts its larvae 
might have. I have long given up breed- 
ing or collecting heterocera (though for 
several years I bred sphinges and bomby- 
cidae largely) , the North American Diurn- 
als giving me more work than I can 
properly attend to; but I had some 
curiosity to satisfy in this particular 
case. I tied the subject to a tree, and 
during the night it was impregnated, and 
next day, 19 April, it laid many eggs. 
The hatching began 1 May. ‘The first 
molt took place 7 May; second molt, 
11 May; third molt, 15 May. On 22 
May, or 7 days after third molt, the first 
larva was shut up in its cocoon. I was 
much surprised at this, as I had expected 
four molts, and I searched the books to 
see what had been said about this 
species. (To be continued on p. 171.) 
