Acid phosphatase, N-acetyl- β-D-glucosaminidase, β-alactosidase and β-glucuronidase were investigated in the normal corneas of several animals (rabbit, calf, bovine, dog, pig, and sheep) by means of biochemical and histochemical methods. The results of both approaches show a wide interspecies variety which are, in general, in good agreement. Pig and sheep corneas show lower activities of all enzymes investigated than those of other animals. The best correlation was found in the case of acid phosphatase which is highest in all animal species under investigation, and is most active in the epithelium as could be proved histochemically. On the other hand, acid glycosidases are more pronounced in keratocytes than in epithelial and endothelial cells. Sequence of activities of individual acid glycosidases, determined by quantitative analysis and histochemical methods, is discussed.