22 



CHARLES F. W. McCLURE 



TABLE 6 



Showing rate at which endothelium of the caudal fin lymphatics may store the dye in 

 advanced toad and frog larvae (July and August) 



7. EXPERIMENTS WHICH SHOW THAT THE METHOD OF VITALLY 



STAINING TYPICAL TISSUES BY IMMERSING YOUNG LARVAE 



IN SOLUTIONS OF COLLOIDAL ACID DYES, CAN ALSO BE 



APPLIED TO YEAR-OLD LARVAE OF R. CATESBIANA 



AND TO ADULT ANURA 



A. Year-old larvae of R. catesbiana (Solutions of low concentration) 

 Experiment 8. Four year-old tadpoles of R. catesbiana were 

 placed in a 1 : 1500 solution of trypan blue in the morning of June 

 26. The liver and mesonephros were removed daily from one of 

 the tadpoles and sectioned. 



a) The tadpole killed on June 27 (1 day in dye) measured 

 sixty-five millimeters in length. Serial sections showed that no 

 dye had been stored in the stellate cells of the liver or in the epi- 

 thelium of the mesonephric tubules. A large lightly stained mono- 

 nuclear cell containing fine dye granules was occasionally found 

 in the intertubular tissue of the kidney. 



