_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
_Form._--Similar to the preceding species, but snout more pointed, the raised canthi rostrales meeting at an acute angle. Eye usually as large as in _V. berus_, nearly as large as the nasal shield; its horizontal diameter equal to its distance from the posterior or anterior border of the nostril, its vertical diameter equal to or a little less than its distance from the mouth. Length of tail seven and a half to nine times in total length in males, eight to ten times in females.
_Head-Shields._--Rostral as deep as broad or a little deeper than broad, just visible from above, and in contact with a single apical shield. Distinct frontal and (usually) parietal shields, the former once and two-thirds to twice and one-third as long as broad, as long as or longer than its distance from the end of the snout, usually longer than the parietals; the latter always in contact with the former, unless broken up into small shields. Two to six, usually three or four, small shields on the snout between the canthals, of which there are two on each side, the second broadly in contact with the supraocular. Supraocular well developed, extending posteriorly beyond the vertical of the eye, separated from the frontal by one to four shields. Nine to eleven, usually ten, scales round the eye, the upper preocular usually in contact with the nasal; either a single series of scales between the eye and the labials, or two series except under the centre of the eye, which is separated from the fourth labial by a single scale. Nasal single. Temporal scales all smooth, or the upper faintly keeled. Upper labials, eight or nine, fourth or fourth and fifth below the eye. Four (rarely five) lower labials in contact with the chin-shields, of which there is but one pair.