1. The hemorrhagic, procoagulant, anticoagulant, phosphodiesterase, hyaluronidase, alkaline phosphomonoesterase, 5'-nucleotidase, arginine ester hydrolase, phospholipase A, L-amino acid oxidase and protease activities of 30 samples of venoms from nine species (12 taxa) of the old world vipers (Subfamily Viperinae) including snakes from the genera Bitis, Causus, Cerastes, Echis, Eristicophis and Pseudocerastes, were determined and the Sephadex G-75 gel filtration patterns for some of the venoms were also examined. 2. Examination of the biological properties of the venoms of the Viperinae tested indicates the presence of common venom biological characteristics at the various phylogenic levels. 3. Venoms of most species of the Viperinae examined exhibited characteristic biological properties at the species level, and this allows the differentiation of the Viperinae species by differences in their biological properties. 4. Particularly useful for this purpose, are the effects of venom on kaolin-cephalin clotting time of platelet poor rabbit plasma and the Sephadex G-75 gel filtration pattern and arginine ester hydrolase activity of the venom.
1. The hemorrhagic, procoagulant, anticoagulant, phosphodiesterase, hyaluronidase, alkaline phosphomonoesterase, 5'-nucleotidase, arginine ester hydrolase, phospholipase A, L-amino acid oxidase and protease activities of 26 samples of venoms of 13 taxa of Vipera were determined and the Sephadex G-75 gel filtration patterns for some of the venoms were also examined. 2. The results indicate the presence of certain common characteristics among the venoms, particularly if V. russelli is excluded from the comparison. The results also support the recently proposed reassignment of V. russelli to a separate genus. 3. The data show that information on venom biological properties can be used for differentiation of venoms of many species of Vipera. Particularly useful for this purpose are the protease, phosphodiesterase, phospholipase A and the procoagulant activities and the Sephadex G-75 gel filtration patterns of the venoms.