The Ecology of a Sheltered Clay Bank 259 
cies to the essential but subordinate characters. The 
individual animals adjust themselves to one another, 
and to the environment, as the personalities in the play 
adjust themselves to one another and to the conditions. 
‘‘In both groups some individuals are dominant, some 
used and useful, some are tolerated, some pick up the 
crumbs, still others are predatory or parasitic, and all 
must be mutually adjusted to one another and to the 
environment.’’ 
On this little stage of the clay bank we have seen en- 
acted the tragedies and joys of life and love, birth and 
death of many creatures; their tolerance of, or indiffer- 
ence to one another, their craftiness in preying upon one 
another and their alertness in escaping persecution, the 
artisans at work, the visitors and the varying outcome 
of their visits—all these things and many others per- 
taining to the lives of a hundred insect species for a day, 
a season, or a succession of years. 
We have seen the pioneers blazing the trail, the rent- 
ers following hard by, and the parasites ever on hand 
keeping in check the otherwise rapidly increasing races ; 
we have seen some that are transitory and some that 
visit, prefer to remain, and may prove either a benefit 
or a burden to the group. 
And finally we have seen their behavior toward the 
elements of nature, to sunlight and cold, to darkness 
and to rain; all these little creatures would come and 
go, act and react, conscious or unconscious of one an- 
other and of the environment. All of the relations and 
interrelations which have controlled them, and all of 
the influence which they have wielded upon each other, to 
bring this social unit to the degree of development or 
balance in which we find it in the present years of the 
