of non-migratory Insects. 181 
Caldcleugh relates in his “ Travels in South America,” 
that he experienced in 22° north latitude, a violent gale 
accompanied by thunder, lightning, and a waterspout, 
and that afterwards, on the deck, and in the tackle, a 
number of butterflies were found. 
Cornelius, in referring to the two preceding facts, 
points out, that here we meet with swarms of butterflies 
in casual connection with grand natural phenomena, such 
as strong gusts of wind and violent tempests, and that it 
seems to him very well admissible, that during great 
storms, but especially in the course of waterspouts and 
tornados, a large number of such insects are swept to- 
gether, and carried over land and sea.* The same author 
observes, that, in preference, he would assert this for 
mixed swarms, consisting of several kinds of insects. 
An instance of such an assemblage is related by Van 
Bemmelen, f who met with unspeakable numbers of white 
butterflies, principally Pieris brassice, one or two species 
of Sphex, and Diptera agreeing with Musca vomitoria, 
Linn., arriving from the sea in the Downs near Nordwyk 
aan Zee, at eleven o’clock, a.m., on the 13th July, 1855. 
On reaching the Downs, they lessened the rapidity of 
their flight; some settled, others kept on their course. 
The flying past was observed for an hour; the direction 
was W.N.W. to E.S.E., the wind was W.N.W., and 
gentle. 
The above are by no means all the observations re- 
ferring to the occasional transportation of non-migratory 
insects which have been made, but I opine that enough 
has been said to prove that, whenever atmospheric dis- 
turbances occur suddenly, considerable numbers of more 
or less stationary insects are likely to be, or are in reality, 
removed to distant quarters. Who has not seen the 
clouds fly overhead with astounding rapidity, and what 
insect could resist the direction of the current of air thus 
indicated, even for hundreds of feet away from the moving 
mass?. In mountainous districts particularly, the clouds 
as they closely encircle a peak for a time, must often 
bring or carry off such castaways. 
A local phenomenon connected with the forced dis- 
persal of living beings, occurs constantly on the Alps; I 
* « Wanderthiere,’ p. 255. 
+ Handelingen nederl. Entom. Vereen, 1857, p. 91. 
TRANS. ENT. Soc. 1871.—rarT u. (MaAy.) O 
