Excretion in reptiles; nitrogen constituents of the urinary concretions of the viviparous snake Eryx thebaicus, Reuss.

The urinary constituents of this animal are excreted in the form of dry masses or concretions. They are generally white in color, but they sometimes contain greenish yellow patches. Unlike those of Zamenis diadema (1) they are not brittle, but rather hard. When examined microscopically they were found to consist principally of club-shaped crystals together with rosettes and globular crystals showing radiating striations. The material used in the present work was collected from nine healthy animals kept in the laboratory. The procedure followed in the present investigation is the same as that of Paper II (1).