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CATERPILLARS. 181 
dry or withered food; and it would obviously take too much time to 
provide fresh leaves for them every day ; besides which, they should be 
moved or handled as little as possible. In some way or other, then, the 
food must be kept fresh ; and this is effected either by sticking the stalks 
into damp sand, or else by putting them into a small bottle of water. In 
the latter case, we must take care that the water does not run out, by 
placing or supporting the bottle in an upright position; and, in addition 
to this, we must provide against the larve getting in, and coming in 
consequence to an untimely end by drowning. This they are prone to 
do ; and, in order to circumvent their propensities, it is well to wrap the 
food-stalk round with cotton wool, paper, or some other material, so that 
it may fit accurately into the neck of the bottle. By this means, food 
may be kept fresh sometimes for weeks, and much time and trouble 
saved to the collector. 
With regard to food, a few hints may probably prove of service. Of 
course, when we can, we should feed our caterpillars upon the tree, 
shrub, or plant upon which they are found in astate of nature. But 
sometimes, from various causes, this is impossible. We may not know 
upon what plant, out of several growing together, a caterpillar has fed; 
or we may have taken it at a distance from home, and be unable to 
obtain a fresh supply. In such cases as these, what are called ‘ substi- 
tute foods” come in very usefully; and upon this subject some valuable 
remarks may be found upon pages 34-38 of Dr. Knaggs’ ‘‘ Lepidopterist’s 
Guide,” which is in the library of this society. 
But, speaking generally, our best chance of success will lie in 
offering to the caterpillars some plant belonging either to the same genus 
or to the same family as that upon which it feeds naturally; and for 
this purpose a little botanical knowledge is requisite. Sometimes, how- 
ever, we do not know even so much as this; and then we must fall back 
upon what are called “ generally favourite foods,” such as knot-grass for 
the larve of Geometers, and plantain, dock, and lettuce for those of 
Noctusz. Itis not a good plan, however, to crowd the breeding cage, 
either with food or with too many caterpillars. We shall stand a far 
better chance of rearing the perfect insects if we confine ourselves to a 
moderate number of caterpillars than if we take all we can find. And it 
is desirable to remove all dead stalks of food, as well as other decaying 
matters, pretty frequently, if we wish to ensure the well-being of our 
charges, taking care, however, to look the old food well over, as other- 
wise we shall be very likely to throw away some of the caterpillars with 
At. It will be necessary, too, to supply now and then fresh water to the 
bottles which hold the food, and likewise to examine the fresh leaves 
before we put them in, so as to avoid introducing with them slugs, 
earwigs, beetles, or spiders, which will sometimes do great damage 
before they are discovered. Against cannibal caterpillars I have 
cautioned you before. But there are other enemies still worse, because 
very difficult (almost impossible) to guard against—I mean the tribe of 
Ichneumons, It is hardly too much to say that more than half of the 
caterpillars which we find abroad have already within their bodies one or 
more mortal foes in the shape of the larve of Ichneumons, which will 
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