No. 10.— The Rattle of the Rattlesnake. By SAMUEL GARMAN. 
Tue habit of sloughing is common to all the serpents. A short time 
before the removal takes place, the new epiderm makes its appearance 
beneath the old. Its presence is easily detected by a whitish color 
under the outer layer. The milky tint of the second layer extends over 
the whole body; on the eyeball it interferes greatly with the sight. 
During the time of its formation, several weeks, while the vision is 
affected, the snake prefers seclusion, and is disinclined to partake of 
food. Some days before casting, about a week in the most recent case 
followed, the milkiness vanishes, the skin resumes its ordinary aspect, 
and the sight becomes again as keen as formerly. By rubbing the lips 
the slough is loosened around the mouth, then it is pushed over the 
head to the neck, whence it is taken back over the body. From the 
neck backward it is, in some cases, removed by means of a coil or two of 
the tail, the body being crowded through and the epiderm left behind. 
A hole in the ground or between rocks, the sticks in a brush heap or 
the stalks in the grass, answer the same purpose as the ring made by 
the tail. Some manage to get the coat back until under the ventral 
scales, when the latter are used somewhat as in gliding, their free 
hinder edges catching and stripping off the slough as the body is moved 
slowly forward. From the hinder part of the body the removal is an 
easier matter: the-loosened portion is caught around a stick or under a 
stone, and with a pull the balance is taken off in an instant. The 
slough comes away like damp paper ; it is wet with a sticky mucus on 
the inner side, turned outward in the operation. The mode of growth 
and of removal is similar among the rattlesnakes. These snakes differ 
in retaining a portion of each slough, that covering the tip of the tail, 
to form one of the rings of the rattle. The attachment is purely me- 
chanical; the rings are merely the sloughs of the end of the tail. 
On the majority of the snakes, both the venomous and the non- 
venomous, the tail tapers more or less gradually toa point. At the 
end it is protected by a sub-conical cap of the epiderm. Under the 
latter lies the skin, and under it again the termination of the vertebral 
column, —a bone formed of vertebree that have coalesced and changed 
VOL. XIII. — NO. 10. 
