BEHAVIOR OF ANURA TOWARD COLLOIDAL DYES 23 



6) On June 28 (2 days in dye) dye granules were observed in the 

 epithelium of a few of the tubules in the mesonephros and a mere 

 trace of dye was found in some of the stellate cells of the liver 

 capillaries. Mononuclears containing dye granules were occasion- 

 ally found in the capillaries of the liver and in the intertubular 

 tissue of the kidney. This larva measured eighty-two milli- 

 meters in length. 



c) On June 29 (3 days in dye) the stellate cells of the liver 

 capillaries were more deeply stained than in the tadpole killed on 

 June 28, and dye granules were also abundant in the epithelium 

 of certain tubules in the mesonephros. Mononuclear cells con- 

 taining dye granules were found in the liver capillaries and in the 

 intertubular tissue of the mesonephros. This tadpole possessed 

 rudimentary hind limbs and measured eighty-two millimeters 

 in length. 



d) On June 30 (4 days in dye) dye granules were abundantly 

 distributed in the cytoplasm of the stellate cells of the liver 

 capillaries and in the epithelium of certain tubules in the meso- 

 nephros. Deeply stained mononuclear leucocytes were also pres- 

 ent in the liver capillaries, intertubular tissue of the kidneys and 

 in the spleen. This tadpole possessed rudimentary hind limbs 

 and measured ninety-four millimeters in length. 



It will be observed that these experiments still further bear out 

 the view that the storage of dye granules may be accomplished 

 in a relatively short time, when larvae are placed in acid dye 

 solutions at an advanced stage of development. 



B. Adult anura (Solutions of high and low concentration) 



Experiment 9 a). An adult toad (Bufo lentiginosus) was allowed 

 to remain in a finger bowl containing a 1 : 100 solution of trypan 

 blue for several hours daily between July 16 and July 22, inclu- 

 sive, and killed on July 23. The actual length of time the toad 

 remained in dye during the course of seven days was sixty-one 

 hours. 



On removing the skin from the abdomen the muscles presented 

 a bluish-green appearance. The alimentary canal was filled with 



