MOULTING OF GRUBS. 



175 



ternal skin only that these gruhs cast, like serpents; 

 but the throat and a part of the stomach, and even the 

 inward surface of the great gut, change their skin at 

 the same time. Yet this is not the whole of these won- 

 ders; for at the same time some hundreds of breath- 

 ing-pipes within the body of the grub cast also each its 

 delicate and tender skin. These several skins are 

 afterwards collected into eighteen thicker, and, as it 

 were, compounded ropes, nine on each side of the 

 body, which, when the skin is cast, slip gently and 

 by degrees from within the body through the eighteen 

 apertures or orifices of the tubes before described, 

 having their tops or ends directed upwards towards the 

 head. Two other branches, also, of the breathing 

 pipes, that are smaller and have no point of respira- 

 tion, cast a skin likewise. If any one separates the 

 cast little ropes, or congeries of breathing pipes with 

 a fine needle, he will very distinctly see their several 



Exuvia and pulmonary vessels of the rhinoceros beetle (Oryctes nasi- 

 cornis). A, magnified view of a pulmonary branch and vesicle; a n, 

 pulmonary branch, composed of a membranous sheath and cartilagi- 

 nous rings; 6, vesicle. B, larva; c c, nine reddish breathing holes. 

 C, exuvia, or cast skin of the larva , d d d d., skins of the pulmonary 

 tubes. 



