The venom of Crotalus adamanteus when administered intravenously to rabbits in properly graded doses causes lesions of the glomerulus of tile kidney which may be either hemorrhagic or exudative in character. Both types of lesion are usually associated but either one or the other may predominate. The hemorrhagic lesion, which may be confined to the glomerular tuft, or, by rupture of the latter, may involve the capsular space, is a peculiar localization of the hemorrhage so common in other parts of the body in venom intoxication. On the other hand, the exquisite exudative lesion involving usually the capsular space but sometimes limited, as in the hemorrhagic type, to the tuft itself and with little or no tubular injury, constitutes a type of experimental vascular nephritis, hitherto undescribed, which differs widely in its anatomical appearance from that due to arsenic, cantharidin and other vascular poisons. As the limitation of the lesion to the glomerulus indicates a selective action of the venom, and as the histological changes in the tuft are suggestive of gradual endothelial destruction and solution, the lesion can be explained by the action of the endotheliolytic body of crotalus venom described by Flexner and Noguchi.