77 
5 
which a viper secures its prey. The fangs which inflict the wound 
are very interesting. In the upper jaw there are two teeth, which 
are so jointed that they can be closed into the gums in the roof of 
the mouth, or turned so that their points come forward and project a 
little beyond the top lip. These teeth, which are the fangs, are 
moreover tubular even to their points, and at the other ends are 
connected, by means of ducts, to glands which secrete the venom. 
When the viper wishes to inflict a poisonous wound it opens its jaws 
almost at right angles, throws forward the fangs, and plunges them 
into the flesh of its victim. As the teeth enter the skin the poison 
glands contract by means of powerful muscles, forcing the venom 
contained there down the ducts and out of the hollow teeth deep into 
the wound. The fangs are then instantly withdrawn, the whole 
operation occupying but a few seconds. This species cannot be 
recommended as a vivarium specimen, though it is exceedingly 
handsome (12 to 15 inches). 
Ifany who read these notes would care to keep a vivarium, there are 
several preliminary precautions to be observed if success is to attend 
the effort. An empty glass aquarium will make a tolerably good case, 
but a little ingenuity and a Tate sugar-box will make a better one. 
In the former all the ventilation will have to come down through 
the top, in the latter suitable holes can be made in the sides near 
the bottom tis well, which will keep the air circulating perfectly 
throughout. This .second method is very much more healthful than 
the first. The bottom of the case should be covered with moss, and 
it is a good plan to keep one portion of it quite dry and the other 
part very moist. In this way the creatures can choose which they 
t prefer to lie under, and their choice will not always be the same. 
Virgi.i cork bark should be liberally supplied for shade and hiding 
places, and a few small branches will add to the natural look of the 
case. A vessel full of clean water should always be there in such a 
place that the inmates can drink without the slightest difficulty. 
The vivarium should never be allowed to remain in strong sunshine 
unless the creatures within are known to naturally live in such a 
tropical atmosphere. Tortoises and alligators will live together 
comfortably, but snakes should never be confined with lizards or 
many of the latter will disappear. 
' The Author is indebted to the Proprietor of the Bedford Conser- 
vatories, Covent Ga'-den Market, London, for the loan of many of 
• the rarer specimens figured in the illustrations. 
