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dark color. After this there is a gradual (but in some instances 

 a very abrupt) change to the normal greenish-yellow coloration. 

 The average time required for animals homoplastically grafted to 

 regain their usual color is twenty-six days from the date of the 

 operation. The change from almost black to yellow is usually 

 a gradual process, parts of the tadpole body turning yellow, other 

 portions retaining the dark color, thus giving the animal a sort 



B 



C 



Fig. 2 A, normal control; B, engrafted larvae; C, engrafted animal following 

 resorption of the graft. 



of mottled effect. Three cases were observed of larvse resuming 

 the yellow color overnight from a deeply pigmented condition. 

 In figure 2 the same tadpole is shown darkly pigmented in B, 

 and in C, twelve hours later, it has changed from dark to yellow. 

 Histological examination of the grafted tissue of such indi- 

 viduals reveals clearly the reason for the resumption of normal 

 coloration in these tadpoles. The graft has, for the most part. 



