Abstract
Summary
1. Lensectomy only and lensectomy combined with retina removal was performed in adult newts 4-8 days after the excision of the thyroids, the hypophysis or both. The results were compared with those in control experiments. Normally lens regenerates reach full shape and structure about the eighth week when cell nuclei of the primary fibers disappear. Rate of regeneration as well as growth of lens were distinctly diminished after retina removal. Early stages of retina regeneration proceeded for about 2 weeks before a lens vesicle was formed. Retina differentiation might be completed during the fifth week. 2. Measurements of lenses showed that regenerates developing in the presence of a regenerating retina were much behind those in eyes with the retina intact. Development rate in both kinds of eyes was very similar when eyes of normal and of gland-deprived animals were compared. In the latter, retina regeneration was not significantly retarded. The size of the lens regenerates at various dates after the eye operation was considerably less in gland-deprived animals. Gland removal seemed to increase the incidence of malformed regenerates and of cataracts. The incidence of cataract was also increased in normal controls after removal of the retina.
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