1883.] Recent Literature. 637 
30,096, and for an equal area in the vicinity of Ithaca, 51,984. At 
the rate of sixty-six per square mile, an area somewhat less than 
that of our State (Wisconsin) would have a population of 3,565,- 
” He then, after stating some facts, concludes: “ Fifty in- 
sects of the average size would certainly be a small daily allowance 
for the average bird. One hundred and twenty days is less than. 
the time our summer residents are with us. At the rate assumed, 
each bird would consume 6000 insects. This would give as the 
aggregate number of insects consumed by the birds calculated to 
occupy an area equal to that of our State, the enormous total of 
21,384,000,000. Add to this amount the work which these birds 
do in their Southern homes, and we have a low estimate of the 
influence they exert over insect life.” After discussing a number 
of topics, the author devotes the body of the essay to an account, 
original and compiled, of the insectivorous habits of 295 species: 
of birds. The work is rich in new facts, is the result of a great 
amount of field-work, and is creditable both to the author and the 
State, which has called for such work. Due credit is done to Mr. 
S. A. Forbes, the pioneer in this line of practical biology. 
THE ZooLocicaL RECORD FoR 1881.— Zo the Editors of the 
American Naturatist:— While thanking the editors of the 
American Naturauist for the appreciatory notice of the “ Zod- 
logical Record” for 1881, contained in their April number, I 
wish to be permitted to offer some explanation on one or two 
points referring to that volume contained in the subsequent notice 
of the German “ Zoologischer Jahresbericht” for the same year. 
€xpert in one branch as to the importance of his subject may 
differ from those of his fellow-workers on the value of detail ; 
want of space was an important factor on this point; and it is 
obviously useless to give (e. g.) the full and often verbose title of 
Paper, 
Palzontological papers were also originally deemed not proper 
Subjects for a zodlogical record, save in recent forms bearing on. 
existing animals. There is, moreover, a separate medium for 
“se papers in the Palzontological section of our “ Geological. 
Record.” Here again, however, the individual opinions of the 
have been allowed to have weight; and the marvelous 
