4o6 Transactions of the Canadian Institute [vol. ix 



Explanation of Plates. 



The figures were drawn with the camera lucida. The distribution 

 of potassium salts is indicated by the black shading which represents 

 the cobaltous sulphide reaction given by the triple sale of potassium, 

 sodium and cobalt hexanitrite when ammonium sulphide is applied to it. 



Fig. I. Kidney tubule, frog, diuresis with K2HPO4; the potassium, sales 

 were washed out of the freshly cut section, which was then 

 treated with the cobalt and sodium, hexanitrite reagent in the 

 usual way. X 820. 



Fig. 2. Kidney tubule, frog in inanition. X 820. 



Fig. 3. Kidney tubule, frog, in the dorsal lymph sacs of which }4 c.c. 

 of 30 per cent, dextrose solution had been injected 4 hours 

 before it was killed. The frog had previously been kept 

 several days in a room of about 20° C. temperature. X 820. 



Fig. 4. Kidney tubule of frog which had been kept for several days in 

 warm room, then pithed and injected with i c.c. of half 

 saturated Na2S04 solution, 17^^ hours after which it was 

 killed. X 820. 



Fig. 5. Kidney tubule, frog, taken from cold room (temperature about 

 10° C.) into the dorsal lymph sacs of which 4 c.c. of 30 per 

 cent, dextrose had been injected four hours before it was 

 killed. X 820. 



Fig. 6. Kidney tubule of frog which had been kept for several days in 

 warm room and into which 4 c.c. of a half-saturated solution 

 of Na2S04 had been injected two hours before it was killed. 

 X 820. 



Fig. 7. Cells from kidney of frog which had been subjected to excessive 

 Na2S04 diuresis, a, leucocyte; 6, red blood cell; c, epithelial 

 cell. X 820. 



Fig. 8. Kidney tubules of frog into which had been injected 4 c.c. 

 ^ K2HPO4 and which was killed two hours later. X 820. 



N 



Fig. 9. Portions of two kidney tubules of frog in which 4 c.c. lo KI had 

 been injected. Animal killed five minutes later. X 820. 



Fig. 10. Portions of three kidney tubules from same preparation as 

 Fig. 9. X 820. 



Fig. II. Kidney tubules, dog, A.C.E. anaesthesia, otherwise normal. 

 X 820. 



