THE CATERPILLAR. 



•found in very young caterpillars of the Orange-tip, and in 

 some others of the " Whites " (Pzeridce). The odd thing about 

 this baby caterpillar is that the fine hair arising from each wart 

 is forked at the tip (Fig. I, a\ and holds thereon a minute globule 

 of fluid. When the caterpillars become about half grown these 

 special hairs are lost in a general clothing of fine hair. Fig. i, b, 

 represents a magnified single ring of the caterpillar, and this 

 shows a spiracle and the folds of the skin {subsegments). The 

 manner in which such folding occurs is to be observed in the 

 higher study of larval morphology. 



On each ring, except the second (including now the three 

 thoracic with the 

 nine abdominal," 

 and so making 

 twelve rings), the 

 third, and the 

 last, there is an 

 oval or roundish 

 mark which indi- 

 cates the position 

 of the breathing 

 hole {spiracle). 

 Through these 

 minute openings 

 air enters to the 

 breathing tubes (trachea), which are spread throughout the 

 interior of the caterpillar in a seemingly complicated kind of 

 network of main branches and finer twigs ; air is thus conveyed 

 to every part of the body. In the event of one or two air-holes 

 becoming in any way obstructed, the caterpillar would possibly 

 be none the worse ; but if all the openings were closed up 

 effectually, it would almost certainly die. Total immersion in 

 water, even for some hours, is not always fatal. 



Turning again to the " feet " of the caterpillar, it will be seen 



Fig. i. 

 Young caterpillar of Orange-tip highly magnified. 

 {After Sharp.) 



