652 



BUTTERFLY. 



"Two deadly weapons first he bore, 

 Strongly outlanced towards either side, 

 Like two sharp spears his enemies to gore 

 So did this fly outstretch his fearful horns, 

 Yet so as him their terror more adorns." SPKMSEK. 



Or, lastly, who has not perceived the beautiful spiral 

 apparatus which they employ in extracting the nectar 

 of flowers ? 



We do trust that there are many amongst our 

 readers who have been sufficiently imbued with the 

 spirit of observation to have noticed these things, 

 since they will thereby have attained a knowledge of 

 the chief characters by which this beautiful group of 

 insects is distinguished from the other lepidopterous 

 tribes. 



" The velvet nap which on his wings doth lie, 

 The silken down with which his back is dight, 

 His broad outstretched horns, his airy thighs, 

 His glorious colours and his glistening eye." SPENSER. 



We have hitherto, however, seen the butterfly only 

 in its final and glorious state , let us now look at it in 

 the earlier stages of its life. " Were a naturalist to 

 announce to the world the discovery of an animal, 

 which for the first five years of its life existed in the 

 form of a serpent, which then penetrating into the 

 earth, and weaving a shroud of pure silk of the finest 

 texture, contracted itself within this covering into a 

 body without external mouth or limbs, and resem- 

 bling more than any anything else an Egyptian 

 mummy ; and which, lastly, after remaining in this 

 state without food and without motion for three years 

 longer, should, at the end of that period, burst its 

 silken cerements, struggle through its earthy cover- 

 ing and start into day a winged bird, what, think 

 you, would be the sensation excited by this piece of 

 intelligence?" In this striking manner do the authors 

 of the Introduction to Entomology introduce the 

 interesting subject of the metamorphoses of insects, a 

 subject which, from the numberless variations in which 

 it is to be observed, merits the most fixed attention. 



The butterflies, indeed, rarely enshroud themselves 

 in a cocoon, but the measures which they take to 

 supply its want are far more remarkable, even than 

 the formation of a silken case spun from the mouth. 



The female butterfly deposits her eggs upon such 

 plants as are proper to nourish the caterpillars which 

 proceed from them ; thus the common white butter- 

 flies place them upon cabbages, the tortoise shell and 

 peacock butterflies upon nettles, &c. These eggs are 

 simply attached by some glutinous secretion to the 

 leaves or stems, without any of that curious precau- 

 tion of inclosing them in down, which takes place in 

 some species of moths. 



The caterpillars which are disclosed from these 

 eggs are for the most part, at first, of a dark colour, 

 previous to their first moulting, which takes place at 

 the end of several days after their birth ; after this 

 event, however, they appear with their respective 

 colours. They are of a long and cylindric form, com- 

 posed of twelve segments, exclusive of the head, and 

 with nine spiracles on each side. Some are slightly 

 hairy, others quite smooth, and many have simple or 

 branching spines upon the different segments of the 

 body. The majority are furnished with sixteen feet, 

 of which six are scaly and attached, in pairs, to the 

 three first segments, and the remaining ten are mem- 

 branous. In the three anterior pairs of legs are 

 inclosed the rudimental legs of the future butterfly. 

 During their growth, and before arriving at their full 

 size, they shed their skin several times, an operation 



which, although perfectly natural, and which only lasts 

 in general three or four minutes, is often exceedingly 

 painful, and causes the death of some caterpillars, 

 which, owing to some circumstance or other, do not 

 possess sufficient strength to accomplish it. At this 

 period of its existence, its head is furnished with a 

 pair of very powerful horny jaws almost of a trian- 

 gular form ; a pair of lower fleshy jaws, and a fleshy 

 lower lip united to the latter, and furnished with a 

 curious apparatus for spinning silk. The sides of the 

 head are likewise furnished with twelve simple and 

 globular eyes, exceedingly minute, scarcely percep- 

 tible, and totally unlike the eyes of the future butter- 

 fly. It now feeds voraciously upon leaves, gnawing 

 them to pieces with its powerful jaws. Having, how- 

 ever, arrived at its full size, and being in this state 

 incapable of reproducing its species, it now prepares 

 for those singular changes of form and functions, 

 which arc destined to end in the production of a 

 creature perfect in its kind. It now ceases to eat, 

 voids whatever portion of its food remains unassimU 

 lated, quits the leaves, and seeks a secure situation in 

 which to undergo its inactive arid helpless state. 

 We have said that the majority of the chrysalides of 

 butterflies are not inclosed in a cocoon, few of them 

 likewise descend to the ground to undergo their 

 transformations. How then can an animal, having 

 completely cast off its outer covering, furnished with 

 legs, and appearing in a state in which the rudiments 

 of legs are completely soldered to the body and 

 incapable of rendering the least assistance, support 

 itself from falling to the ground? This is a problem 

 which it would be most difficult to solve, and yet the 

 difficulty is overcome by the caterpillars in several 

 different manners, and which depend in a great mea- 

 sure upon the position in which the future chrysalides 

 are destined to be placed ; some being suspended in 

 the air vertically, head downwards, the tip of the tail 

 being the only point of attachment to a twig or leaf ; 

 others, on the contrary, are attached against walls, 

 &c., having the head higher than the tail, and many 

 are placed horizontally, these being attached not only 

 by the tail, but by a skein of silk passing across the 

 middle of the body. It is to Reaumur that we are 

 indebted for a precise account of the manner in which 

 the different manoeuvres employed by these cater- 

 pillars are effected. We will notice first the manner 

 in which the suspension of chrysalides is performed, 

 a process which may be observed by every one in 

 the common tortoise-shell butterfly, which is found 

 upon every bed of nettles. Reaumur asks how is 

 the circumstance to be accounted for, that the chry- 

 salis is found hanging precisely in the same place as 

 we had observed the larva suspended, seeing that 

 when the latter is attached, every portion of the 

 chrysalis is covered by the skin of the larva ; it is 

 therefore the tail of the caterpillar which we had 

 seen attached in the very same spot where we now 

 perceive the tail of the chrysalis. It might be ima- 

 gined that the skin of the caterpillar was slit from the 

 head to the tail, or that the tail of the chrysalis had, 

 in some manner, been protruded through the skin of 

 the caterpillar ; but neither of these circumstances 

 takes place : the skin of the latter only bursts a short 

 distance down the back, and the tail of the chrysalis 

 is entirely concealed within the envelope of the 

 caterpillar. Moreover the difficulty is increased by 

 the threads to which the tail of the chrysalis is sus- 

 pended, being spun by the mouth of the caterpillar. 



