PATTERNS OF CELL-PROLIFERATION IN THE DEVELOPING RETINA OF THE CLAWED FROG IN RELATION TO BLOOD-SUPPLY AND POSITION OF THE CHOROIDAL FISSURE

The pattern of retinal vasculative in Xenopus is described. The position at which cell proliferation at the ventral retinal margin is maximal is at the point of entry of the ventral blood vessels. To test whether there is a causal relation between retinal blood supply and retinal cell production, surgical inversion of the eye, transplantations and excisions of retina were done to change the pattern of retinal vasculature. The growth pattern of inverted eyes was normal with respect to the internal axes of the eyes. After excision of part of the retina or after fusion of retinal fragments to form compound eyes, the pattern of retinal cell proliferation was not correlated with the distribution of retinal blood vessels but was correlated with the position(s) of the choroidal fissure(s).