148 Journal of the Asiatic Society of Bengal. [N.S., XVIII, 
urine produced, whence it is obvious that if the glomerular 
blood pressure is to be controlled the glomerulus must be 
available for the urine pressure to act upon, i.e. the glomerulus 
communicating with the tubule. A similar condition is demand- 
ed by the pump theory. If the glomerulus or glomus contracts 
previous to each heart beat, then, in order to act asa pump, urine 
must immediately flow into the capsule or other cavity from the 
tubule and the secretion pressure in the tubule being temporarily 
lowered by the capsular inflow, more urine must be formed in 
the tubule; when the glomerulus expands it will expel the 
recently formed. The pump theory therefore demands a 
residual amount of urine which flows to and from the capsule 3 
and which is only used in expelling urine more recently secreted, 



deed both authors (13) furnish evidence of its probability when they state 
that the capsules (and tubules) of an active obstructed (ureter constricted) 
kid e more distended with accumulated fluid than those of an 
i ul i 


iv 
transposed at the head of the measurements supplied by these authors). 
1 Brodie and Mackenzie state that in the inactive kidney ‘‘ the 
glomerular surface always lies in contact with the capsule wall ”—the ex- 
planation of which is that the glomerulus and capsule are already s¢ 
shrunken that heat and aleghol have not much power to produce diffe - 

