_Habits._--Only a few specimens have hitherto been found in Italy and in France, but the species occurred up to a few years ago in extraordinary numbers in Lower Austria, in the immediate vicinity of Laxenburg. The intendant of the imperial castle pays a premium for the destruction of Vipers, and in the course of one year (1892) more than 1,000 specimens were brought to him. These snakes are found principally, though not exclusively, in the marshy meadows around the park, where they may be seen about in the daytime from May to September, feeding chiefly on lizards (_Lacerta agilis_), and also on small rodents. The lizards are swallowed as soon as seized, without the effect of the poison being awaited as in other Viperid snakes. This Viper is as a rule of gentle disposition, allowing itself to be handled without attempting to bite, and village boys have been seen playing with them. Although occurring in such enormous numbers at Laxenburg, no accident from snake-bite has ever been heard of. The form from the Balkan Peninsula (_V. macrops_) is even more pacific still, and is believed never to make use of its poison apparatus, its food consisting of orthopterous insects. According to Captain Veith, who has collected a large number of specimens of this Southern form, the contents of the stomach as well as the excrements show this snake to feed exclusively on grasshoppers. On one occasion a big specimen showed such a swelling of the body as to lead to the conclusion that it had swallowed a mouse, but it soon after disgorged what proved to be a ball made up of the agglutinated remains of at least a hundred grasshoppers. When handled, this Viper hisses or even pretends to snap, but with closed mouth, never biting unless seriously hurt. The poison appears to have little effect on man. _Reproduction._--Nothing has been published on the breeding habits of this species, but in a letter to the author, dated January 14, 1913, Herr L. von Kirchroth, who has examined over 4,000 specimens since 1890, says the young are born in July or August, exceptionally as early as June. Young females bring forth from six to eight young, older females from eight to eighteen; but a large female from Lower Austria is reported to have contained as many as twenty-two. The length of the new-born young is from 5 to 6 inches, and it grows rapidly within the first week, probably through stretching out, without taking any food. According to Captain Veith, the form described as _V. macrops_ brings forth only from three to five young. 22. VIPERA RENARDI, Christoph Renard's Viper