1890.] Entomology. 1213 
25. London Purple on Peach, by A, J. Cook, reviewing spraying 
experiments in Michigan and at Cornell University. 
26. Life-History of White Grubs, by S. A. FonBES, showing that all 
our common species pupate in the fall, and describing early stages of 
several species. 
27. Life-History of the Corn-Plant Louse, by S. A. FORBES, report- 
ing investigations during a number of years by which many new points 
in the life-history of this insect bave been brought out. 
In addition to these numerous papers, the discussions throughout 
were of unusual interest. The entomologists are certainly to be con- 
gratulated on the large attendance and number of papers, as well as 
the evident desire manifested throughout the sessions to help each 
other in forwarding the work in which they are engaged.— CLARENCE 
M. WEED. 
The Screw Worm.— Two bulletins concerning this insect ( Com- 
psomyia macellaria) have lately been issue he first is by 
Francis, of the Texas Experiment Stadion; and the second by Prof. 
H. A. Morgan, of the Louisiana Station. That by Dr. Francis is quite 
short, but gives illustrations of all the stages of the insect, engraved 
. from drawings by Miss Freda Detmers, which are shown at Plate 
XXX Dr. Francis quotes from a letter in which Dr. S. W. Williston 
states that the fly ** occurs everywhere from Canada to Patagonia,’’ but 
adds that only in Texas is it of economic importance in the United 
States. Cattle are especially liable to attack, but horses, mules, hogs, 
sheep, dogs, and in some recorded cases even men, are attacked. Dr. 
Francis continues : 
* In all animals alike, the eggs, after being laid by the fly, hatch 
into larva or so-called * worms,’ e exact length of time this re- 
quires seems to vary with circumstances, My present opinion is that, 
if the eggs are laid in a moist place and on a warm day, it requires 
less than one hour ; whereas, if laid in a dry place they seem to dry up 
and lose their vitality. The young larve when first hatched are small 
and easily overlooked. If they are hatched on the surface in a drop 
of blood from a ruptured tick, for instance, they attempt to perforate 
the skin, and if hatched in wounds they at once become buried out of 
sight. They seem to attach themselves by their heads, and burrow their 
way under the skin, completely devouring the soft flesh. Occasionally 
a few are seen moving from one place to another, but usually they re- 
main fixed at one point. The worms grow steadily in size, and the 
hole in the flesh becomes larger every day. Sometimes the worm 
makes tunnels, but not to any depth ; they usually stay on the surface. 
