798 THE AMERICAN NATURALIST. | [Vor. XXXVI. 
distances away.! Dr. Henry C. McCook, in his great work on 
American Spiders and their Spinning Work, has shown how 
the huntsman spider, Heteropoda venatorius, on account of its 
aeronautic habits, might well have circumnavigated the globe 
with the aid of the trade winds, basing his calculations on the 
localities where the spider is known to occur and the direction 
of these winds. The late Dr. D. S. Kellicott told me of the 
sudden appearance of considerable numbers of the cotton-worm 
moth, Aletia argillacea, at Columbus, Ohio, immediately fol- 
lowing a gale from the southwest ; and, besides, we know that 
this moth has been found as far north as western Ontario, 
with no evidence of its having developed there in a single 
instance. Years ago, while studying the habits of the buffalo 
gnat, in the Southern States, one of the most perplexing ques- 
tions that confronted the planter, relative to the habits of this 
bloodthirsty insect, was their sudden appearance in a locality 
in such immense swarms as to kill thousands of head of cattle, 
mules, and other domestic animals, before these could be gotten 
toa place of safety. Early in my investigations, I found that 
the adult gnats emerged from the waters of the bayous and 
clustered upon the surrounding vegetation in such numbers as 
to fairly cover the same, and a sudden high wind would carry 
these gnats along with it and distribute them for miles over 
the cotton plantations, there to carry on their bloody work. 
Thus, these insects might appear suddenly in immense num- 
bers, ten or twelve miles from their place of breeding, in one 
direction, while in the direction opposite they might not occur 
1 Since the preparation of this paper the following note has come to me: 
The ‘Blue Page’ Moth. — During the gale that reached Barbados and St. Vin- 
cent on August 26, 1901, numbers of a large moth were found in Barbados, of 
a kind not known to breed there. They had evidently been brought by the 
high southwest wind. Some were caught and identified as Urania sloanei, the 
‘blue page’ of Trinidad, and they had apparently come from the mainland or, 
more probably, from Trinidad itself. They were found as far north as Dominica, 
an 
direct distance from Trinidad to Barbados is about 160 miles, and to Dominica is 
. Some roo miles more. — The (Barbados) Agricultural News, June 7, 1902- 
