12 



THE CLASSIFICATION OF INSECTS 



organs themselves. Nevertheless, if we carefully watch the process of the last 

 moulting, or, rather, if we are successful in removing gently the larva-skin before 

 the pupa is hardened, we see that all the above-mentiolied organs exist in reality, 

 wholly independent and entirely free from each other, (Figs. 14, 15, 16, 16 a, 17, 

 18, 19, 19 a,) though still imperfectly developed, since the legs are mere cylindrical 

 tubes without regular articulations (a, a); since the antenna present a similar 

 tubular appearance, somewhat swollen towards the end, but without joints 

 (6, h) ; since the maxillse project as two independent tubes, also very much like 

 another pair of legs (c, c) ; and since the wings appear as four distinct, swollen, 

 but somewhat flattened vesicles {d, d), identical in appearance with the lateral 

 respiratory vesicles of Annellides, sufficiently large, however, to remind us of the 

 wings as they appear when the perfect insect has come out from the chrysalis. We 

 have, therefore, an apparently complete butterfly, somewhat imperfect in its char- 

 acters, coming out from the larva with all its parts independent, prior to the period 

 when these parts are pressed upon the sides of the animal, and soldered with its 

 walls. 



The process by which these parts are pressed flat, and made to adhere to the 

 body, is connected, no doubt, with the act by which the pupa escapes through 

 the narrow slit on the back of the skin of its larva ; but when the larva-skin is 

 gently removed, and the pressure prevented, these parts will all remain free, and 

 dry up in an irregular connection, and shrivel in an irregular fusion. Or if, imme- 

 diately after the removal of the larva-skin, the young animal be placed in water 

 with a few drops of alcohol, the parts will remain expanded, and may afterwards 

 be preserved in that condition in a stronger liquid. So that we may derive imper- 

 fect butterflies directly from larvae, sufficiently similar to the butterfly which escapes 

 from the pupa to be readily recognized, and presenting all the characters of the 

 perfect butterfly, except the imperfect articulations of the legs and antennge, the 

 unconnected maxillse, and the vesicular wings.* 



The position of these wings is rather symmetrical. They are bent backwards 

 and downwards, the upper surface outside ; and this is the case even in those 

 Lepidoptera which, when full grown, fold their wings upwards, with the upper 

 surface turned inwards, and the inner or under surface outwards. This fact is of 

 great importance, as it shows that all the Lepidoptera, which naturally keep their 

 wings bent downwards in the form of a roof, must be considered as lower, in their 



* These facts, which I believed to be entirely new to science when I first observed them, have already- 

 been noticed to some extent, and are mentioned in the following manner by Burmeister, in his Manual of 

 Entomology, p. 426 of the English translation : — " After the third moulting, when the larva has acquired 

 its full size, the rudiments of the wings begin to form beneath the skin, upon the first and second seg- 

 ments. They at first present themselves as short viscous leaves, the substance of which greatly resem- 

 bles that of the mucous tunic, and to which many delicate tracheae pass, which distribute themselves 

 throughout them. These rudiments increase with the growth of the caterpillar, and betray themselves, 

 even externally, by both the segments of the caterpillar, upon which these rudimentary wings are found, 

 appearing swollen and spotted. Their enlargement probably takes place by the assistance of the blood 

 flowing into them. Simultaneously with the perfecting of these rudiments, the intestinal canal increases 

 m compass, and, as a consequence of this increase, there is a greater accumulation of the fatty mass. A 



