14 BUTTERFLY COLLECTOIl'S 



who have spent years in their contempUition ; and who luive 

 not only attended to tiieir habits, hut niiimtely examined 

 their stnictiire and intenial conformation. One species of 

 motion peculiar to Caterpillars is their mode of climbing and 

 descending, which they cftect by ladders or a single rope. 

 The Caterpillar of Pontia Brassha; the large white or cab- 

 bage Butterfly, scales walls and even glass windows, without 

 difliculty ; but in the last instance, if the square upon which 

 the animal is travelling be examined with a microscope, a 

 visible track like that of a snail may be seen. This consists 

 of little silken threads which it has spun in a zig-zag direc- 

 tion, forming a rope ladder, by which it ascends a surfaee it 

 could not otherwise adhere to. These threads being of a 

 gummy nature, harden in the air and easily attach themselves 

 to the glass. Some of the Lejndopterous Caterpillars are 

 solitary, wliile others live in society. " A Caterpillar, when 

 grown to its ftill size, retires to some convenient spot, and 

 securmg itself properly by a small number of silken filaments, 

 either suspends itself by the tail, hanging with its head down- 

 wards, or else in an upright position, with the body fastened 

 round the middle by a proper number of filaments. It then 

 casts off the Caterpillar skin, imd commences chrysalis ; in 

 which state it continues till the enclosed Butterfly is reiidy 

 for birth, which, liberating itself from the skin of the chrysa- 

 lis, suddenly quits the state of inactivity to which it had been 

 so long confined, and becomes at pleasure an inhahitimt of 

 the air."* 



This wonderful resuscitation has been so spiritedly des- 

 cribed by the French poet of nature, that no apology will, I 

 tnist, be required for the insertion of the following extract 

 from his " Jardme." 



» Shaw, vol, vi. p. 206. 



