586 
Miller and Carlton—The Cat’s Kidney. 
The separate results were not accurate and so he solved the 
problem in another way. Certain portions of the cortex of the 
kidney of the pig were cut out and weighed. After teasing the 
mass apart in HOI, the glomeruli were counted. A mass 
weighing 15.5 centgrm. was examined in this way and found to 
contain 720 glomeruli. This gave 46.4 glomeruli to every 
centgrm. A kidney was then taken and cut into thin sections 
and the cortex separated from the medulla and fat. The weight 
was as follows: 
Cortex. 102.0 gr. 
Medulla.. 12.5 gr. 
Fat and vessels in sinus renalis. 6.0 gr. 
The amount of cortex in the pig is very large when compared 
with the amount of medulla. In the entire cortex (102 gr.) 
there would be 473,200 glomeruli, or in round numbers 500,000. 
According to his previous estimation of volume., the 99,000 cu. 
mm. of cortex contained 473,200 glomeruli, or five glomeruli to 
every cubic millimeter. They are not uniformly distributed, 
but lie in the labyrinth of the cortex between the medullary 
rays. 
Huschke (cited by Schweigger-Seidel) estimated there were 
over two million glomeruli in the human kidney. Every 
Malpighian pyramid of the cortex contained 700 renal lobules, 
and each lobule contained 200 uriniferous tubules, which in a 
kidney of fifteen pyramids gives 2,100,000 uriniferous tubules 
and same number of glomeruli. Schweigger-Seidel calculated 
the volume of this number of glomeruli and found it to be one- 
eighth of the entire volume of the kidney, and hence regarded 
the calculation as incorrect. He thinks there are about six 
glomeruli to every cu. mm. The uriniferous tubules must make 
up in length what they lose in numbers. 
No reference could be found as to the number of glomeruli in 
the kidney of the cat. A medium-sized kidney was well in¬ 
jected with Prussian blue gelatin. The cat was chloroformed 
and killed by bleeding. A canula was inserted in the abdomi¬ 
nal aorta below renal arteries and the aorta was tied about 
one inch above the arteries. All traces of blood were washed 
out with physiological salt solution after which the kidneys were 
