Effect of thyroxine on the permeability of the isolated toad bladder.

Abstract

THE hermaphrodite gland of the slug Arion ater rufus is pigmented, and changes in the degree of pigmentation are correlated with the sexual stages in the gland1. In the early stages of development the hermaphrodite gland is translucent, but during spermatogenesis it becomes opaque and grey in colour, at the oocyte stage dark brown and ultimately, after oviposition, black. The final dense pigmentation is due partly to a gradual increase in the amount of pigment, partly to concentration of existing pigment by shrinkage of the gland.