1884.] Analyses of Books. 285 
species only are mentioned, — the yellow rattlesnake ( Crotalus 
durissus ) and the massassanga ( Crotalophorus tergemina). We 
cannot agree with Dr. Hoy when he pronounces the Crotalidae 
the most deadly poisonous serpents known. 
Mr. M. Strong gives a list of the mammals, in which the diet 
and habits are tersely summarised, and an opinion is given as to 
whether they merit preservation or extirpation. Most of the 
squirrels are shown to be decidedly harmful, as destroying corn 
and eating the buds of trees. 
Mr. King furnishes a very instructive chapter on the “ Econo- 
mic Relations of Wisconsin Birds.” This report is founded on 
an examination of the contents of the stomachs of over 1800 
birds. “ The contents of one-half of the stomachs were exa- 
mined under the hand-lens on the day they were obtained, while 
the contents of 750 were transferred at once to small phials con- 
taining alcohol, and carefully labelled.” This material, by the 
permission of Prof. Comstock, was studied in the Entomological 
Laboratory of Cornell University. The author lays down the 
following preliminary propositions : — A bird renders a service 
when it is injurious or destructive to plants which are to be re- 
garded as detrimental. Mr. King, indeed, considers that the 
mere aCt of cultivation so effectually controls these weeds that 
but little work is left for birds to do. We can scarcely accept 
this in view of the persistence, if not the increase, of many of 
the more noxious weeds. In England, at least, the farmer seems 
to gain little ground in his war with the thistle, the red sorrel, 
the groundsel, &c. 
Mr. King next states that a bird renders a service when it feeds 
upon injurious mammals, such as squirrels, gophers, rats, mice, 
and hares. Further evidence is here given of the damage done 
by squirrels, especially Sciurius Hudsonius, in devouring the 
eggs and young of the small insectivorous birds. Again, a bird 
may do service by feeding upon injurious birds and reptiles. 
Concerning snakes it is pointed out that much remains to be 
learned. Many species, not direCtly hurtful to men, do us indi- 
rect disservice by preying on frogs and toads, newts, fish, small 
birds, &c. Hence a snake-devouring bird is to be regarded as 
beneficial except it has counterbalancing habits. 
The greatest service which birds render us is, however, in the 
destruction of noxious inseCts. We here meet with a passage 
against which we must put in a decided protest. Mr. King 
writes : — “ Wherever the English sparrow, the bird so much de- 
cried in our country of late, has been exterminated in Europe, 
noxious inseCts are said to have followed in such abundance that 
it has not only been gladly reinstated, but is now protected be- 
cause it accomplishes what parasitic and predaceous inseCts are 
unable to do.” If such an assertion is made in any scientific 
treatise, as distinguished from the mythology of zoophilism, 
the alleged multiplication of noxious inseCts will be due to the 
