The Ecology of a Sheltered Clay Bank 209 
bees, and hence kept at a discreet and respectful distance. 
However, one man was a factor to be reckoned with in 
considering the enemies of the unit—that was the ob- 
server. That he should rightly be considered as a non- 
resident part of this ecological unit is evidenced by the 
fact that, in taking specimens for identification, he dis- 
rupted the fine balance of nature, but actually no more so 
than if he had been a lizard and captured these insects for 
food. He took only those species which were unknown to 
him, and then took them in minimum numbers. However, 
in some cases he was guilty of swinging the balance to 
some point where, without his interference, it would not 
have stood. Had he not taken the only Halictus, Mega- 
chile and others, these insects probably would have be- 
come established in the bank and their progeny would 
have done their part to modify the life of the community. 
The reader can easily estimate the extent of these depre- 
dations by glancing over the list of the inhabitants and 
noting all the species that have been submitted to ex- 
perts for identification. I do not want to exaggerate 
this point absurdly, but I think it is well that we should 
realize that man is not a thing apart from the other fac- 
tors in the balance of nature, but that he is only one 
species among many in the great game of give and take 
which makes up ecology. 
Lepidoptera. 
Pyralis cuprealis Hubn. (H. G. Dyar]. This visitor 
was found in the beak of a stick-bug, Emesa brevipennis, 
on July 16, 1917. 
Two caterpillars belonging to the Pyralididae. [S. B. 
Fracker] were found promenading on the bank on Sep- 
tember 12, 1917, and later in the day a dead one was 
