Exchange of Eyes Between Adult Hosts of Amblystoma punctatum and Triturus viridescens . ∗

It has been shown by one of the authors that functional eyes can be successfully exchanged between the larvae of 2 closely allied species, Amblystoma punctatum and A. tigrinum. 1 Since we have also demonstrated that homoplastic eye grafts of adult A. puncta-turn 2 and Triturus viridescens 3 , 4 , 5 can be made with return of vision, it was of interest to see what success could be obtained in these 2 very different species if their eyes were exchanged. In the present experiments the right eyes were exchanged between 34 pairs of animals. The Amblystoma hosts were young adults around 10 to 11 cm in length. The Triturus animals were about 9 cm in length. The eyes were studied daily while living and the hosts were preserved from 14 to 141 days after operation for histological studies.

In Amblystoma eyes on Triturus hosts return of circulation was observed as early as the fifth day. In the majority of cases it was recorded during the first 2 weeks. In Triturus grafts it was first seen on the sixth day and recorded in one-half of the cases during the first 2 weeks. In some cases temporary opacity in the cornea in both groups delayed the observation of the first visible signs of circulation. In some Triturus eyes the opacity, when it appeared, lasted for many days. Corneal reflex was obtained in Amblystoma grafts after the first month. This appeared to be present in a few Triturus eyes also.

The experiments demonstrated that Amblystoma eyes were far better adapted to their new hosts than the Triturus grafts. Although there was sloughing and resorption of both types of grafts the Triturus eyes on Amblystoma if kept long enough beyond the sixth or seventh week ended in this way.