WATER MARGIN 219 
The day was warm and a strong southeast wind was blowing. In mid- 
afternoon there was a small shower and the wind changed to a strong 
northeaster. At 4 P.M. we paid another visit to the beach. The waves 
were rolling moderately high and the beach was covered with a host of 
insects, chiefly alive, though many were dead. The beach was lined 
with live forms crawling away from the water. Often the live ones 
were still clinging to small sticks upon which they had floated ashore 
by the fifties. These insects represented all orders, belonging to various 
habitats near the lake. There were large forest margin bugs, potato- 
beetles, lady-beetles, horseflies, robber-flies, butterflies, water, marsh, 
prairie, and forest inhabitants which had been blown in the lake in the 
forenoon. With them were occasional fish, some with large round scars 
showing the work of the lampreys (166); others that had evidently died 
from other causes. On other occasions dead muskrats, dogs, cats, birds 
of all kinds have been found in these lines of drift (167). On one 
occasion, birds, chiefly downy woodpeckers, were so numerous that 
one could almost step from one to the other, had they been equally 
spaced over the half-mile of beach upon which they were strewn. Need- 
ham (168) has studied the drift and gives an account of the numerous 
beetles that came ashore. 
In a few days after such a storm, one finds the various insects that 
washed ashore either lying dead, or alive under the chips, sticks, and 
carcasses which came with them. Flesh-flies detect the presence of the- 
food very quickly, and often come to dead fish inside of ten or fifteen 
minutes (169). These flies belong to the families Sarcophagidae and 
Muscidae. As a result of storms which float the bodies of animals 
ashore from time to time, the flies always find a sufficient quantity of 
decaying flesh to maintain the species. The flies are in competition with 
a large number of scavenger beetles: e.g., a hister (Saprinus patruelis 
Lec.) which feeds on carrion (Stereopalpus badiipennis Lec.). Several 
species of rove-beetle complete a partial list of the other scavengers 
usually more or less abundant on the shore. The larvae of Dermestidae 
have been found under the dry remains of fish which had been worked 
over by the carrion-feeders. 
Preying upon these and upon the insects that come ashore are the 
tiger-beetles (Cicindela hirticollis and cuprascens) (151, 170) which pick 
up the flies that they often are able to seize while alighting on the ground. 
They also capture the maggots of the flies when they leave the carrion, 
and the lady-beetles and other small insects which come ashore. Several 
species of the ground beetles and occasional shore bugs (Saldidae) are 
