1881. } Entomology. 147 
Experiment 4—Twelve cabbages: one gallon water to one 
spoonful of the powder. Result, thirteen dead, four alive and 
four stupefied. 
The above experiments show conclusively that this powder is 
fatal to the caterpillars, and that too in very dilute liquid mixtures, 
as Only s}y of a lb. to the gallon of water was used in Exp. 2 of 
Oct. Ist, and eleven larve were killed, We have only to sprinkle 
it on to the plants, though it may be necessary to make more than 
one application to insure complete success. The success was 
better with the liquid than with the flour mixture, and can be ap- 
plied with greater speed and econom 
A twig of alder (Alnus serrulata), covered beneath with wooly 
Aphides (Fviosoma tessellatum Fitch), was dipped into the liquid 
mixture of #5 lb. to a gallon of water. The next morning all the 
lice had fallen to the ground, never to rise again. 
Flies and mosquitoes in a room where the powdered Pyrethrum 
had been blown in not very large quantities, less than y}y of a Ib. 
to a room twelve feet square, were felled to the floor, where nearly 
all remained till morning; though the application was made the 
night before. If not swept up some of the flies would recover. 
The flies commence to fall in ten minutes. 
Squash bugs ( Coreus tristis), were kept in the clear powder, ina 
close tin box, for three days, and were still alive. I also sprinkled 
and dusted these insects on the vine, and could see no signs of 
success in killing them. : 
E Foop oF Fisurs.—We have received an interesting con- 
tribution, with the above title, by Prof. S. A. Forbes, from Bulletin 
No. 3, Illinois State Laboratory of Natural History, November, 
1880. The author gives the results of a large series of examina- 
tions of the stomachs of darters, perches, bass and sunfishes. He 
also separately considers the food of the young fishes as distin- 
guished from that of the adult, His investigations have led to 
some interesting general conclusions, among which we commend 
the following as applying to studies in other departments of 
these depend. He must likewise study the species with which it 
comes in competition, and the entire system of conditions affect- 
