﻿INTEGUMENT 21 



the apparatus is intended. At each exuviation one 

 bell-shaped horny piece is added. The number of 

 segments in the rattle is, therefore, not an index to 

 age, as formerly believed ; nor is it to the number of 

 exuviations, for w^hilst segments are being added at 

 the base of the apparatus the terminal ones break 

 off and are lost. A Crotalus sixteen months old may 

 have six pieces to the rattle if there have been six 

 exuviations and no loss. No rattle appears ever to 

 comprise more than about twenty pieces, even in old 

 specimens. The size of the terminal button show^s 

 whether it was formed at birth or at any later period, 

 no growth taking place in the horny tissue. 



So far as trustworthy records are concerned, the 

 largest snakes known, the Malay Python reticulatus 

 and the South American Anaconda, Eunectes murinuSy 

 reach a length of 25 to 30 feet. Measurements of 

 skins must be accepted with caution, as a skin may 

 easily be stretched to once and a half its real length ; 

 in estimating the exact length from such a stretched 

 skin, it is necessary to deduct the interstitial spaces 

 showing between the scales, and about one-fourth of 

 the scale to allow for the overlap. The smallest 

 snake known is 4 inches long {Glaucoma disstmilis). 

 The largest European snake (Coluber quatuorlineatus) 

 is reported to reach a length of 8 feet ; the smallest 

 {Typhlops vermicularis) does not exceed 14 inches. 



