MOULTTNG OF GRUBS. 



75 



it is not the external skin only that these grubs cast, 

 like serpents ; but the t hroat 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 wonders ; for at the same time some hun- 

 dreds of breathing-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 respiration, cast a skin 

 likewise. If any one separates the cast little ropes or 

 jongeries of breathing-pipes with a fine needle, he 



Exuvia and pulmonary vessels of the rhinoceros-beetle [OrycteB 

 nasicornis^. A, niae:nified view of a pulmonary branch and 

 vesicle ; na, pnlmonary branch, composed of a membranous sheath 

 and cartilaginous ritig:s; 6, vesi(;le. B, larva; c c, nine reddish 

 breathing-holes. C, exuvia, or cast skin of the larva; d d d d, 

 skins of the pulinoiidry tubes. 



