3891.) Biological Work of American Experimeut Stations. 231 
Mendenhall, “the inestimable value of being of no practical 
utility whatever.” But surely this is an error. I believe that 
every addition to our knowledge of the biology, classification, or 
distribution of an animal or plant will sooner or later be found 
useful. The organisms about us are so intimately related to each 
other and to their environment that we cannot say to one or 
a few of them: “Thou art of practical account; thee alone will 
we study.” For when we come to investigate even the smallest 
insect thoroughly, we find that it is simply a part of a vast and 
complex organism, and that it is vitally related to other creatures `- 
in a thousand ways. It is preyed upon by “the fowl of the air 
and the fish of the sea”; frogs are ever ready to lick it up with 
their viscid tongues, and toads are lying in wait to send it in 
search of the mystic jewel within their bodies ; quadrupeds in 
great variety esteem it a delicate morsel, and other insects devour 
it bodily’, or suck out its life-blood, or gnaw away its vitals ; bac- 
terial germs are ever ready to destroy it, and the spores of Cor- 
dyceps and Empusa are but waiting an opportunity to develop 
within its body; its alimentary canal may contain a rich and varied 
fauna and flora, revealed only by the microscope, and the plant 
upon which it feeds is subject to a thousand agencies that make 
for its weal or woe. In short, it is engaged in an intense struggle 
‘for existence, and an adequate knowledge of the insect itself 
necessarily involves a consideration of the forces engaged in the 
struggle. 
In the same way, if we would learn the economic status of a 
bird, we must study its food, its habits, its enemies. To do this 
properly involves an acquaintance with a large portion of the 
flora and fauna where the bird occurs,—not a mere knowledge of 
species, but an acquaintance with their habits and histories. And 
an adequate knowledge of a plant involves a study of a vast num- 
ber of organisms,—a study of the insects that attack its roots; 
- those that burrow in its stems; that feed upon its leaves, within 
or without; that visit its blossoms ; that mine its fruit; of those 
that find in its foliage or flowers concealment from prey or pro- 
tection from enemies ; of the birds that devour its fruit and scatter 
its seed ; of the quadrupeds that browse upon its foliage or Baw" 
