No. 380.] FALSE PREMISES IN ECONOMIC ZOOLOGY. 573 
nivorous mammals, mice, rats, gophers, and ground squirrels, as 
a class, are noxious ; (2) birds, in their widest acceptation, 
which form the food of our hawks and owls are largely of 
species beneficial to agriculture ; (3) reptiles and batrachians 
forming the prey of rapacious birds in the United States are, 
as a class, probably as noxious as otherwise; (4) insects 
preyed upon by these birds belong largely to noxious species ; 
(5) of all the species of animals which are devoured by our 
rapacious birds in the eastern United States none is so largely 
and universally devoured or so harmful to agriculture as the 
common meadow mouse (Microtus pennsylvanicus). 
I have striven to make these formule a conservative sum- 
mary of the doctor’s standards of good and bad as adopted in 
this valuable work. If it is a just summary, the author 
believes that the 1893 basis of judgment of our zodlogists 
in Washington is destined to undergo a radical change in some 
respects. It may already be doing so. Certain it is that the 
ideas conveyed in propositions æ, c, and e are more or less 
erroneous, and in some features show a trace of the traditional 
prejudice which even scientific men often find it difficult to 
banish from their investigations. 
To avoid misunderstanding, let us take the most flagrant 
case of a so-called noxious mammal, one which forms the bulk 
of the food of several of our hawks and owls which are nowa- 
days rightly classed as the farmer’s friends. The common 
vole, or meadow mouse (Microtus pennsylvanicus), belonging to 
the same subfamily of rodents as the northern lemming, is 
rated by nearly all who know him as the incarnation of agri- 
cultural pests. On this standard, and this alone, have Drs. 
Warren, Fisher, and Merriam based their verdict of the eco- 
nomic value of nearly two-thirds of the eastern species of hawks 
and owls which appear on their rolls of honor. The rough-leg 
hawk is accorded first place on this list because he eats almost 
nothing else but meadow mice of this species. But it is a 
Stubborn fact that the case of the meadow mouse has never 
been proved against him. Not a tithe of the study devoted to 
his devourers has been given to him, and no scientific analysis 
of his stomach contents or food habits has yet been put on 
