130 Journal of the Asiatic Society of Bengal. [N.S., XVIII, 
glomeruli (a very small percentage of the total number) showed 
traces of the dye. 
PART IV. 
THE TUBULES VERSUS THE ENCAPSULATED GLOMERULI—A 
BRIEF CONSIDERATION OF THE PROBABLE FUNCTIONS OF 
THESE TWO PARTS OF THE VERTEBRATE KIDNEY. 
CONTENTS. 
other Perfusing Fluid (Volume x Rate of Flow) traversing the 
Inter ubular Plexus and not on Fluid Pressure in the Glo- 
meruli. 
(2) Reversal of the Current of Perfusing Fluid through the Kidney. 
(3) The Quality of the Urine is dependent on Fluid Pressure. 
the Pressure in the Arterial Fluid. 
(5) The Increase and Decrease of Urine due to the Increase and 
ecrease of the Osmotic Pressure of the Fluid traversing the 
Renal Afferent Veins. 
Alternative Hypotheses to account for the Enclosure of the Glome- 
: : rulus in the Capsule. 
A Consideration of some other Arguments used in support of the 
neo-Ludwig Theory. 
In Parts I-III of this Memoir it has been necessary on 
several occasions to refer to current theories concerning the 
mode of function of the kidney, since our interpretation of the 
Bowman-Heidenhain theory, the second the neo-Ludwig theory 
(the “ modern theory ” of Cushny, 17), and the third that which 
tubule are of essentially the same order (17, pp. 40, 56) 1s 
: : 
development of “this very special apparatus,” the capsule 
with its glomerulus? There remain then the neo-Ludwig 
theory, which as is well known, assumes filtration through the 
