tee 
re) 

1922. ] ‘* Renal Portal”’ System. 151 
] 
stances, it is necessary to concentrate or otherwise alter the 
composition of in-coming substances, then the kidney is not an 
isolated exception but is, on the contrary, an excellent example 
of conformity to rule, and the only exception to this rule would 
be the renal tubule epithelium if, as Cushny assumes, it absorbs 
unchanged the Locke’s fluid portion of the glomerular filtrate. 
We further object to the additional supposition—advanced 
with the same object in view—that because the gland cells of 
the kidney differ from all other gland cells in being developed 



! See the author’s papers published in the Proc. Zool. Soc. London, 
19°1, p. 183, and Anat. Anzeig. Bd. 40, 1911, p. 225, 

