XIII 



VIPERINAE 643 



numbers at the camp-fire. They cannot climb, and they avoid 

 going into water. The pairing takes place as a rule from March 

 to May, a number of individuals, mostly males, collecting around 

 the females, and forming entangled lumps of snakes ; parturition 

 takes place in the following July and August. In exceptionally 

 warm winters they have been known to pair in December, having 

 left their winter-quarters. Tliey hibernate for about six months, 

 more or less according to the climate, congregating in great 

 numbers, sometimes in dozens. With very rare exceptions 

 Vipers do not take food in captivity, but prefer starving them- 

 selves to death. The bite is as a rule not fatal. The seriousness 

 of the case depends of course upon many circumstances, as for 

 instance the state of concentration of the venom, the position and 

 depth of the bite, and last but nob least upon the general condi- 

 tion of health of the victim. General depression aggravated 

 by nervousness, weakness of the bitten limb, occasional breaking 

 out of the wound, are of frequent and protracted occurrence. 

 (See also p. 590.) 



F. aspis is a more southern and western European Viper, 

 occurring from France to the Tyrol, and in Italy. The snout is 

 slightly turned up at the end, and still more so in V. latastei 

 of Spain and Portugal. In V. ammodytes, of South-Eastern 

 Europe, the raised portion is produced into a soft, scaly 

 appendage (see the lower figure on p. 641). Vipers are some- 

 times unpleasantly common in certain localities. This was for 

 instance the case at the drill-ground near Metz, and the military 

 authorities paid a price for each viper delivered to them. The 

 supply of the latter increased to an alarming extent until the 

 German authorities discovered that a regular trade had been 

 established across the frontier, and that the French Lorrainers 

 were importing vipers briskly. 



V. russelli, the " Daboia " or Eussell's Viper, is one of the 

 scourges of India, Ceylon, Burma, and Siam. The scales form 

 about thirty rows on the body. The upper surface of the head 

 is covered with small, imbricating, usually keeled scales. The 

 general colour is pale brown above with three longitudinal series 

 of black, light-edged rings, which sometimes encircle reddish spots. 

 The under parts are yellowish white, uniform, or with small 

 crescentic black spots. Total length up to about 5 feet. The 

 poisoning symptoms are described on p. 590. 



