In the present study the specific and nonspecific cholinesterase activities of the rabbit's retinae in the fetus, the neonatal, the light-isolated, and the reopened group, which consisted of 65 healthy young rabbits, weighing about 300 to 500 gm, 33 rabbit's fetuses, and neonatal rabbits, were histochemically ovserved by means of the cholinesterase method recommended by Gerebtzoff (1953) and the embedding and sectioning method pesented by Koelle and Friedenwald (1950). Cholinesterase activity of the retinae in the 15 days fetuses was not present but began to develop in the 20 days fetuses. In the 1 week group after suturing the eyelids, the most remarkable activity of specific and nonspecific cholinesterase was observed in the posterior polar area. The nearer to the peripheral area of the retina the weaker the enzymetic activities became. In the 2 weeks group after suturing eyelids, the enzymatic activity was reduced. In the 4, and 8weeks groups after suturing the eyelides, the enzymatic activities were remarkably reduced. In the l4 days after reopening eyelide, which group has previously been kept under the condition of light isolation for 4 weeks, enzymatic activities were fairly recovered and compared with the normal control group. Consequently it is histochemically deduced that the gradual change of specific cholinesterase activities in the rabbit's retinae was closely related to the visual function.
Animals ; Animals, Newborn/enzymology ; Cholinesterases/*metabolism ; Histocytochemistry ; *Rabbits ; Retina/embryology/*enzymology