532 
Miller and Carlton—The Cat’s Kidney. 
THE RELATION OF THE CORTEX OF THE KIDNEY TO THE ENTIRE 
AREA OF SECTIONS TAKEN FROM KIDNEYS INJECTED AND 
HARDENED IN ALCOHOL. 
Four pairs of kidneys were partially injected and hardened 
in alcohol. Before hardening they were cut up in three or four 
pieces in the direction indicated in the last column of the table. 
The partial injection served to show the boundary line between 
cortex and medulla very plainly. The kidneys were imbedded 
by the celloidin process and sections cut 35 y thick. The area 
of the entire section and of the medulla and boundary zone was 
found with a planimeter. No estimate of volume of cortex 
could be made because the thickness of the separate pieces was 
not estimated before placing them in alcohol. The areas in 
square decimeters are shown in Table VI. In estimating the 
number of glomeruli .700 was used as the per cent, of cortex 
and not .633, although this is the figure for injected kidneys. 
But in this case the kidneys were only partially injected and 
the shrinkage was considerable. The kidney which was used to es¬ 
timate the number of glomeruli was injected with a constant 
presstire apparatus and when the vessels were filled, the pressure 
was raised and the gelatin packed in. 
