24 CHARLES F. W. McCLURE 



dye and its walls were stained intensely blue. All of the joints 

 and tendinous sheaths near the latter were stained a deep blue. 

 The roof of the mouth and walls of the pharynx were also diffusely 

 stained. The veins and lymphatics of the mesentery were deeply 

 stained but no dye granules were observed in the cytoplasm of their 

 endothelium. The aortic arches near the heart were also diffusely 

 stained. The lungs, testes, fat bodies, nerves and central nervous 

 system were unstained. No white blood-corpuscles containing 

 dye granules were observed in the circulation. Serial sections 

 were made of the liver, kidneys and spleen. 



A study of sections showed that dye had been stored in abun- 

 dance in the cytoplasm of the stellate cells of the liver capillaries 

 and in the epithelium of certain tubules in the kidneys, but no 

 trace of dye was observed in the spleen. Mononuclear cells con- 

 taining dye granules were found in the intertubular tissue of the 

 kidneys. 



6) An adult frog (R. pipiens) was placed in a finger bowl con- 

 taining a 1 : 1500 solution of trypan blue on April 10, in which it 

 remained continuously until April 26, when killed. The liver, 

 kidneys and testes were removed from the body and sectioned. 



Dye granules were stored in abundance in the stellate cells of 

 the liver capillaries and in the epithelium of certain tubules in the 

 kidney. They were also observed in the interstitial tissue of the 

 testis. Numerous mononuclear cells containing dye granules 

 were found in the intertubular tissue of the kidney. 



c) An adult frog (R. clamata) was allowed to remain in a finder 

 bowl containing a 1:200 solution of Niagara blue (dye No. 161) 

 for several hours daily between September 12 and September 28, 

 inclusive, and killed on October 5. The actual length of time the 

 frog remained in the dye during the course of twenty-three days 

 was seventy-four hours. 



The general appearance of the muscles, organs, etc., was 

 essentially the same as that mentioned in Experiment 9 a. A study 

 of sections showed that dye had been stored in abundance in the 

 cytoplasm of the stellate cells of the liver and in the epithelium 

 of certain of the tubules in the kidneys. Mononuclear cells con- 

 taining dye granules were also found in the intertubular tissue of 

 the kidneys. 



