OPHIDIAN A CR OB A TS. 



193 



Having" by accident discovered that they turn aside from 

 this, some Western settlers, when camping out, have 

 effectually entrenched themselves within a circle of horse-hair 

 rope as a barrier to rattlesnakes while sleeping. 



Let us try to account for this. ^ 



Many of my readers have seen the cast-off coat of a snake. 

 Those who have not can have the pleasure of examining one 

 or several the next time they go to the Zoological Gardens, 

 where the obliging keeper will cheerfully exhibit them. 

 Others at a distance may not enjoy this facility, and for 

 these the accompanying diagrams may be a slight com- 

 pensation. 



Portion of slough of a rattle- 

 snake (exact size). 



Ventral scales of the same, and 

 a section. 



The whole cuticle or epidermis of a serpent is composed 

 of these overlapping scales, of which the above illustrations 

 are only fragments. Thus when we speak of their scales, we 

 do not mean distinct and separable laminae, like the scales 

 of some fishes, each of which may be scraped or plucked off, 



.N 



