METAMORPHOSIS OF AMPHIBIAN ORGANS 269 



eye which will be needed later. Experiment 34 was therefore 

 photographed again on October 19, and this time in four times 

 the natural size; the photograph was then painted carefully. 

 This is shown in figure 13. The borders of the graft can now be 

 seen quite distinctly, the graft is still the even color of a larva 

 of A. punctatum, but is slightly darker than the host. The 

 dark patch in front of the eye corresponds to a tumor-like eleva- 

 tion of the grafted skin produced probably by a proliferation 

 of the epithelial cell, such as is often found in examining skin 

 grafts of Amphibians on microscopic sections. The photo-' 

 graph of experiment 33 taken 'on October 10 was enlarged on 

 October 19 but was not painted before February 18, 1917 (fig. 

 14) when the animal was already dead and preserved in formalin. 

 In the period from October 10, 1916 to January 30, 1917 (the 

 date the animal died) the two spots of the graft in back of the 

 eye and particularly the spot in front of the eye, increased some- 

 what in size; the size of these spots in figure 14 corresponds to 

 their size on January 30, 1917, as they were drawn from the 

 preserved specimen. The picture (fig. 14) shows also that 

 besides the difference in size there is a considerable difference in 

 the color of the graft's and host's spots. When the picture was 

 made the colors were painted according to the notes made during 

 the observations of the living specimen, with the aid of other 

 living animals whose color was known to have been similar to 

 experiment 33, and partly from memory; but it is believed that 

 the picture is in color at least, very close to the actual colors of 

 the living specimen. In the preserved formalin specimen all 

 spots are of course, much bleached, but nevertheless the difference 

 between the color of the spots of the host and graft can be seen 

 most clearly. 



b. The metamorphosis of the grafted eye. As previously men- 

 tioned no special attention was paid to the metamorphosis of the 

 eye in this series of experiments on A. punctatum. Only in one 

 pair of experiments (33-34) described in the last chapter, the 

 metamorphosis of the eyes was watched during part of the life 

 of the animal, so as to give a fairly continuous series of observa- 

 tions. An abstract from the notes is given here. 



