THE YOUNG NATURALIST. 



55 



ai rarely long in finding, then they set to work 

 W i a will. Some of them will devour several 

 ti ;s their own weight in a day. The Iarvce of 

 be les, flies. &c, that feed on dead flesh, grow 

 wi wonderful rapidity, and indeed, if they could 

 nifecd up very- quickly, their food would not con- 

 tie in a suitable state long enough for them. These 

 as'ell as othersare invaluable scavengers and save 

 liron? much disease. After they have grown so 

 m h, they cease eating for a while, — longer or 

 slrter, according to the species. Then the skin 

 5|ts at the back, and in a few minutes the larva 

 d vis out of it, as we might draw our hand from 

 a|ove. The larva that was "too big for its 

 clhes," now finds its only garment "a world too 

 «e," and commences to eat again, often making 

 iiirst meal from its cast skin. Again it grows 

 ffkigj again casts off its skin, and so on until its 

 m growth is attained. The larva then retires to 

 m itable place, casts its skin once more, and in 

 mt cases becomes a motionless, helpless object, 

 ^ped a pupa. About the pupae we have some" 

 ■g to say, but it must be reserved for next week. 

 VI will say a few words now about the food of 

 ix. It will be much easier to tell you what 

 it x will not eat, than to enumerate what they 

 jtf. We are not aware of any animal or vegetable 

 iluction that does not serve some of them. The 

 fa of one little moth eats the surface off our 

 ■hes, another attacks the lining of our sofas and 

 Mrs. One larva is eating our cheese, while 



■ her prefers bacon. The larvae of one fly likes 

 ■i meat, while another prefers carrion, and a 



■ 1 will only eat the flesh of a living animal, and 

 4t in this they have their selected food, one 



■ ig mutton, while another will only take beef, 

 ■told you last week of one kind of insect de- 

 nting their eggs in or upon living caterpillars, 



■ the larva of one insect will live inside the larva 

 wnother, carefully avoiding the vital portions as 

 Jvours its substance ; the larva of another will 



■ and devour the entire caterpillar, with perhaps 

 ■ood of ichneumons inside it. The Aphis-lion 

 imrs plant-lice only, while some species will eat 

 § their own kind. Hair, wool, bone, horn, or 

 •substance manufactured from them are equally 

 Icked by one or other of the insect tribe. Turn 

 | e vegetable world and the same thing obtains. 

 »n the dry lichen on an old wall to the mighty 

 ftt tree, evesy part of every vegetable substance 

 ens for food for some species or other of the 



' teeming world of insects, and whilf one kind will 

 devour almost anything that comes in their way, 

 another will eat but one plant or flower. Very 

 little green food comes amiss to the larva of the 

 Tiger Moth (Chelonia oaja). The larvse of the 

 White Butterflies will eat almost any plant of the 

 cabbage tribe (cruriferce), while that of the Small 

 Tortoise-shell confines itself to nettles, and of the 

 Large Tortoise-shell, to elm. One eats the leaf 

 another the bark, a third the wood, a fourth the 

 root. Another tribe insert their ecg~ in the 

 growing shoot, or in the epidermis of the leaf, and 

 the juices of the plant are so turned from their 

 natural course as to produce oak-apples, galls, and 

 other things that the larvse may have suitable food. 

 The voung of many beetles, and some few moths 

 eat solid wood. Some like their food washed with 

 the sprav from the sea waves, another prefers to 

 have it dried, and is most at home in the herbalists' 

 shop, but space would fail, were we to enumerate 

 a tithe of the curious tastes evinced by larvse. 

 Some larvae are aquatic, live below the surface of 

 the water ; of these some breathe air, and need to 

 come to the surface at frequent intervals for a sup- 

 ply, others have branchiae and are quite exposed 

 to the water. Many larvae have the power or 

 secreting a gummy substance from which they can 

 draw out a thread. This is often used for con- 

 structing a cocoon in which they may change to a 

 pupa unmolested. The cocoon is sometimes com- 

 posed entirely of this silk, at others a leaf is drawn 

 together, or bits of soil or other substances incor- 

 porated with it. Some larvse make more use of 

 this secretion. That of the Red Admiral Butterfly 

 (Vanessa ntnhrnta) draws up the edges of a nettle 

 leaf and lives within. The larvae of many tree 

 feeding species, especially geomters, appeartofasten 

 a thread every time they move, and when they are 

 suddenly dislodged by the beating stick or a gust of 

 wind, they hang suspended in air. and are able to 

 climb up the single rope more expeditiously than 

 the most practised gymnast. Some species appear 

 to spin this web wherever they go. One British 

 species, the Small Eggar, (Uriogaster Icmestris), 

 makes a sort of tent with it, which increases in size 

 as they need to travel further for food, for they all 

 live together and return to their domicile after 

 feeding. The silk of commerce is principally the 

 produce of the larva; of Bombyx rnorio, though 

 several other species are now being cultivated for 

 the same purpose. 



