Io MAN AND ANIMALS 
destroyed. The parasites, especially, are often more beneficial to man’s 
interests than the animals which devour them, and which take good and 
bad without the slightest discrimination from our economic point of 
view. Because of their destruction of parasitic insects Severin (8) argues 
that birds should not be protected. Certain mammals and reptiles often 
show a decided superiority over certain birds in this respect, in that they 
are strictly predatory and are not directly noxious at any time of year 
as are some birds which feed upon grain. 
Many animals feed extensively upon insect pests when they are 
numerous and accordingly threaten a crop. This is true of spiders, 
insects (11), amphibians, reptiles, mammals, and birds (8), especially 
those that are largely predatory. This fact is the only sure guaranty 
of the economic value of many birds, and is perhaps overworked by the 
fanciers of the group. This value belongs equally to certain insects, 
so that if birds were not devouring such insects along with pests, these 
hexapods would probably be able to put the pests down. The other 
vertebrates also would probably be able to put down the pest without 
the aid of the birds; Forbes has said that a balance would finally be 
reached if all the vertebrates were exterminated (see 26). 
In the preceding pages we mention “sanity toward nature.” 
Sanity toward nature is based upon a full knowledge of available facts. 
Partial knowledge, if fully depended upon, is as dangerous as falsehood, 
for it leads to false interpretations. We must know nature, not a part, 
but the whole, if we wish to treat the simplest everyday problem of 
our relations to animals intelligently and justly. 
Why protect birds? Is the present attempt justified? In the 
answer to these questions all sentimentalism should be laid aside. It 
is sometimes urged that birds have a greater aesthetic value than other 
animals. This it seems is unjustified unless the songs of some constitute 
the justification. Persons with only a small acquaintance with insects, 
mollusks, fishes, amphibians, reptiles, and mammals find as much beauty 
in these groups as the bird fancier does in his. All groups should be 
preserved for their aesthetic value as the appreciation of it depends 
entirely upon temperament,! training, and especially a knowledge of the 
« A few persons known to the writer are repelled by birds because of their claws, 
scaly legs, and other reptilian characters. Many admirers of nature and animals are 
not attracted by birds because as a rule they must be seen from a distance. Inquiry 
at close range necessitates either shooting or capturing the bird and neither is a par- 
ticularly aesthetic operation. In the case of capture, only a short period of necessary 
neglect usually renders the surroundings and often also the bird not only not aesthetic 
