GERMAN COCKROACH. 27 
greater size of this species distinguishes it readily from both of the 
previously mentioned kinds and ‘‘ ow own’’ Black Beetle, so to call it ; 
and the distinctions of the Blatta orientalis being pitchy-coloured 
without markings; the small German Cockroach, P. germanica, being 
yellowish, with two dark stripes; and the American Cockroach, P. 
_ americana, being much larger than either, and with the yellowish fore 
body with brown mottlings, or two large somewhat rusty spots, appear 
to be sufficiently clear for general purposes. 
The American Cockroach is stated to be found on ‘‘all continents,”’ 
and for those who wish to follow up its destructive habits, the obser- 
vations in ‘Insect Life,’ before quoted from, which can easily be run 
up by reference to the excellent recently published ‘ Index,’ will give 
usefully interesting information. 
I have not as yet had specimens sent me, but from enquiries made 
from time to time, I conjecture that this American Cockroach is pre- 
sent in London, besides its establishment at the Zoological Gardens, 
and that therefore it may be worth while just to draw attention to it. 
PREVENTION AND Remepres.—The remedy most approved of by the 
late Prof. C. V. Riley was fresh and ‘‘ reliable ’’ Pyrethrum or Persian 
insect powder. This to be applied by ‘‘ puffing”’ it with a little hand 
machine into all crevices, drawers, cracks of old furniture, behind 
skirtings, everywhere, in fact, where the insects hide, and next morning 
clearing away all the dead or stupified Cockroaches that are lying 
about, and destroying them. 
Various other insect powders, as Keating’s, for instance, do good, 
if thoroughly applied; but the great point, which is very apt to be 
neglected, is the after treatment. Many of the Cockroaches will be 
only stupified, and if merely thrown aside to a dust-heap, will revive, 
and be perfectly able to fly or walk back, as the case may be, and re- 
establish themselves in their old home or in the neighbourhood. 
Traps sometimes answer well, and a very simple and convenient 
plan is to set a small bowl on the floor, with some beer, or beer and 
sugar, at the bottom, and a few little pieces of stick arranged round, 
resting on the bowl at their upper ends, so as to form roads for the 
Cockroaches from the floor. The insects fall or crawl down into the 
beer, and are drowned or stupified, and if care is taken to throw 
the bodies into the fire, this simple method sometimes gets rid of a 
good many. 
Filling up all chinks and crannies where the Cockroaches may 
harbour, or through which they may pass to and fro, is a very impor- 
tant item in treatment. If something distasteful is mixed with the 
plaster of Paris or rougher plaster used, it is a great safeguard against 
the insects gnawing their way through. Carbolic acid mixed with 
