310 apparatus used by entomologists. 
of the plants may be put for the caterpillars to feed on. The most 
convenient size of the cages is about eight inches in breadth, four deep, 
and one foot in height; they should never contain butone kind of ca- 
terpillar, as some species devour others ; and indeed, if left without 
food, will devour those of their own kind also. At the bottom of each 
case must be a quantity of earth, about two inches deep; with the 
earth should be mixed a little sand, and some of' die title mould fre- 
quently found in the bodies of old trees ; this will prevent in a great 
measure the earth drying up into hard lumps or clods. The. most cer- 
tain way ol breeding insects is to keep the cages in a cool and moist 
place, as in a cellar or out-house; for a great number of caterpillars 
change into the pupa stale several inches beneath the surface of the 
earth, and if kept too dry, the earth about them will absorb the nutri- 
tive moist-ore from the animal, thereby not only weakening it, but 
hardening the shell in which it is inclosed, so that its strength will be 
insufficient to burst the case when it should come forth, and in which 
it must die, as many have done, occasioned entirely by this mis- 
management of them. 
Some years produce a greater quantity of caterpillars than others, 
and keeping each kind by themselves would require an immense 
number of cages, and much time in changing the food, and paying a 
proper attention to them, it is a common practice to have a breeding 
cage of larger dimensions, by which means a great number of cater- 
pillars may be fed in one cage, in which a variety of food may be put, 
but must be taken away and replaced with fresh plants every second 
or third day, for this tends greatly to the obtaining of tine specimens 
of the perfect insect. 
The larva; of many insects that feed beneath the surface of the 
earth may he bred in the following manner: Let any box that is about 
three or four feet square, and two or three feel; dee]), be lined or co- 
vered externally with tin, and bore through the sides and bottom a 
number of very minute holes: put. into this box a quantity of earth 
that is replete with such vegetables as the caterpillars subsist on, and 
sink it into a bed of earth, so that the surface mav hi* exposed to the 
different changes of the weather : the lid should be covered with brass 
or iron net-work, to prevent their escape. 
Cabinet. — In the present advanced state of Entomology, a collec- 
tion of British insects requires a Cabinet of from 50 to 100 drawers, 
which are generally about fourteen or fifteen inches in length and 
breadth, and about two inches in depth ; the cork with which the bot- 
toms are to be lined must he chosen as free from cracks and knots as 
possible, arid filed, or cut very level, and lx: about the sixth of an inch 
in substance. The top of every drawer must be glazed, to prevent the 
admission of dust or air ; the glass is usually fitted into a frame of the 
same size as the drawer, and is made to let in on a rabbet. 
