388 
VERTEBRATA. 
those directed to preventing the poison from getting into tlie circulation, and of these the prin- 
cipal consist in sucking the Avound — either with a cupping-glass or with the mouth, which may 
be done without the least danger, the poison being quite innocuous when taken internally — cut- 
ting out the wounded part, or burning it with a hot iron or Avith caustic applications. All these 
remedies must, however, be adopted immediately after the wound has been received ; if any time 
be allowed to elapse the most distressing symptoms make their appearance, and if these can be 
relieved by the administration of medicines, which, however, appears somewhat doubtful, the 
patient generally suffers for a long period from the effects of the bite. 
The Vipeiina are divided into two families, the Crotalidce, of which the rattlesnakes are the 
types, and the Viperidce, of which the vipers are the types. 
THE KATX1.ESXAKE. 
THE CROTALIDiE 
This family not only contains the rattlesnakes, but a considerable number of other species 
distributed throughout the warm parts of the earth; they are all particularly distinguished 
by the presence of a deep pit on each side of the nose, situated beneath, and usually a little be- 
hind the nostril. This pit, the purpose of which is still unknown, is lined with smaU plates. 
The head is broad and flat, scaly on the crown, and furnished with small shields only on the 
sides and nose. The teeth are very small, but the poison-fangs are exceedingly large and poAver- 
fal; and these snakes must be regarded as among the most dangerous of the order. The belly 
is covered with broad shields. 
Genus CROTALUS : Crotalus. — This includes the Rattlesnakes, of Avhich there are several 
species, all belonging to the continent of America. The Common- or Northern Rattlesnake of 
the United States, often called Banded Rattlesnake, C. durissus, is of a yelloAvish or reddish 
brown, sometimes of a chestnut black, with irregular, rhomboidal, black blotches ; head large, 
flattened, and triangular; neck small; tail short; length from three to four feet, sometimes 
even as much as seven or eight. Like the other Viperina they produce their young alive. 
Upon the tail is Avhat is called a rattle, consisting of several homy enlargements loosely attached 
to each other, and making a loud rattling 
noise Avhen shaken and rubbed against 
each other. These rattles generally in- 
crease Avith the age, but not regularly 
once a year, as is supposed. Tavo and 
even four have been knoAvn to come in a year, and sometimes several of the rattles drop off; 
they are seldom over tAventy-five in number. The use of these extraordinary appendages seems 
KATTLE OF TWENTX-FOUB JOINTS. 
