12 THE ZOOLOGIST. 
track was literally black with small Toads which tried to hop 
away at our approach. The fields and ditches by the line were 
also swarming with Toads as far as could be seen.” 
Unless one has witnessed a flight of Locusts, or the immense 
shoals of migrating fish, it is difficult to imagine the magnitude 
of these swarms. It might help one to realize the conditions of 
such invasions if a swarm on a like scale were to invade the 
British Isles, the length and breadth of which roughly corre- 
spond with the area which my observations show to have been 
actually covered by some of the swarms in the Black Sea and 
Azov—though how much further they travelled ‘south, or from 
how much further north they came, or how wide a space the 
flights covered, I cannot say. My impression is that most of 
these particular flights would be checked by the hills on the 
south of the Black Sea where the wind dies down, for as soon 
as this happens insects, especially beetles, have a tendency to 
drop and settle—a fatal proceeding if they happen to be over 
the sea at the time. At any rate the north-west wind which 
carried the Painted Ladies and the beetles died down as we 
reached the Bosphorus, and I only noticed a few of the former 
at Constantinople, and none after that except one or two on 
board the ship that had most likely been passengers from the 
Black Sea. 
Suppose, then, such a flight of butterflies or beetles covering 
the whole of our islands for the best part of a week—or suppose 
that after a thunder-shower the whole of Middlesex were to 
become black with hopping Toads—I think the papers would 
universally chronicle such events; whereas only a few ocean- 
going tramps pass through these Russian swarms, and the only 
notice taken is evinced by a little extra ‘‘language”’ when the 
beetles or what not mingle with the ‘‘ Harriet Lane” or ‘‘ White- 
chapel Mysteries’”’ in the mess-kids. Of course the moujiks 
ashore never seem to notice anything. 
As I have watched these myriads of wind-borne creatures 
lightly hurrying past for days together the thought often 
occurred to me that, given a continuance of favourable winds, a 
tremendous distance might be traversed before the crowd would 
become too thin to make sure of some settling on ocean islands, 
however small and scattered. 
