THE QUESTION OF HIBERNATION. 
21 
South, and that the first crop raised thereafter was infested. Professor 
Coinstocktook particular pains to make inquiries on this head, and found 
that some patches of cotton had been grown every year in such sections. 
In fttVOT of hibernation in the southern portion of the cotton belt may 
be Urged [1] the appearance of the moth on the wing during mild winter 
M eat her, and its being found torpid in sheltered situations, as is insisted 
on by so many; [2] the first appearance of the worms in very small 
numbers, and in the spring of the year, as attested by recent observa- 
tions; [3] tbeir reappearance each year in the same spots, not on the 
sea-coast Bearcat to the tropical zone, where we should expect them on 
the theory of annual incoming, but at various points far inland ; [4] the 
coming of the moths in large in mbers and as immigrants into the 
northern portions of the belt, being alwars preceded by the appearance 
of the worms and their gradual increase at some other, generally more 
southern or western, points; and [">] the decrease of cotton culture in 
Central America and the West Indies, as appears from market statis- 
tics, and the absolute absence of the worm in the Bahamas since 18li6, 
as as c ert ained by Mr. Bchwari while there in the spring of 1879. 
The strongest fact against hibernation was, perhaps, the period elaps- 
ing between the disappearance of the moths in March and the lirst 
appearance of the worms, or, to put it in another form, the absence of 
the worms on the young ami tender cotton. The period during which 
the species was not observed is already reduced by t lie facts given in this 
report to less t ban one month instead of t hree, and this is much less than 
the time elapsing between the issuing from winter quarters of other 
well-known Lepidoptera that hibernate in the imago state, and the first 
appearance of their larva?, numerous illustrations of which fact might 
be cited. • 
On the whole, therefore, the weight of evidence is strongly against 
the theory of annual extermination, in the southern part of the belt, and 
the fact of the hibernation of Aletia there may be said to rest on as 
good evidence as that of many other species in which it is admitted 
without question. Yet Aletia is beyond doubt killed out each winter in 
the northern portion of the cotton belt, and all the arguments in favor 
of annual extinction and incoming de novo have force when restricted 
to this section. Just where the separating line lies between extinction 
and survival is not so easy to decide, and for the present we can only 
refer to that given in the Introduction as the result of the investigation 
so far as it has gone. This conclusion that the moth does and can hiber- 
nate in the United States does not preclude its occasional incoming from 
foreign, more tropical countries, or the possibility of its being brought 
by favorable w inds from such exterior regions, just as originally must 
have been the case when the species was first introduced. The facts 
indicate, however, that this kind of immigration is less frequent uow-a- 
days than it was in the beginning of the century. 
* The intervening period is still further lessened, as will he seen from the remarks on page 12 and in 
Note 12. 
