BEHAVIOR OF ANURA TOWARD COLLOIDAL DYES 31 



walls of the stomach, distal half of the small intestine and rectum 

 were lightly stained. The proximal half of the small intestine was 

 unstained. The aortic arches near the heart and ventral surface 

 of the vertebral column were deeply stained. 



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

 dance in the stellate cells of the liver capillaries and in the epithe- 

 lium of a few of the tubules in the kidney. A precipitate of the 

 dye was found in some of the venules of the spleen. The endo- 

 thelium of these venules was deeply stained but it was impossible 

 to determine the presence of dye granules on account of the 

 density of the stain. No trace of dye was observed in sections of 

 the testes or fat bodies. Mononuclear leucocytes containing dye 

 granules were abundant. They were observed in sections of a 

 number of tissues, including the mucosa of the duodenum. The 

 presence of phagocytic cells among the epithelial cells of the frog's 

 intestinal mucosa has already been observed by R. Heidenhain 

 ('88), Bizzorero ('92) and others. 



e) This experiment differs from those above-mentioned, in the 

 circumstance that only the hind feet and ankles were suspended 

 in the dye. 



A small adult of R. clamata was suspended for short intervals 

 daily from July 9 to July 18, inclusive, in a 1:100 solution of 

 Niagara blue, and killed on July 19. The actual length of time 

 the frog was suspended in dye during a period of ten days was 

 eleven hours and fifteen minutes. 



On the removal of skin the muscles and joints, except that of 

 the ankle, were found to possess their natural color and with no 

 indication of being stained. None of the viscera appeared to be 

 stained in the slightest degree. 



A study of sections showed that not a trace of dye had been 

 stored in the stellate cells of the liver capillaries. The merest 

 trace of dye, however, was unmistakably stored in the form of 

 granules in the epithelium of a few tubules in the kidneys. Deeply 

 stained mononuclear leucocytes containing dye granules were also 

 found in the intertubular tissue of the kidneys. 



The amount of dye which entered the circulation through the 

 lymphatics of the feet and ankles must have been exceedingly 



