606 Prof. Brodie and Mr. Mackenzie. On Changes in the 

 Hence 



Mean diameter capsule 102 - 4 101*6 



glomerulus 90-6 92*4 



Approximate volume capsule ... 134 131 



„ „ glomerulus 93 99 



fluid 41 32 



Convoluted tubules — 



Proximal. External diameter ... 40'4 4L4 



Lumen 17'8 18-2 



Distal. External diameter ... 25 - 4 29 - 6 



Lumen 17'2 21-0 



grm. 



Weight of E. kidney 15'8 



„ L. kidney 15 - 8 



In this experiment the blood-pressure was low and the flow of urine small, 

 and with it again the volume of fluid in the capsule is small. In general, 

 it confirms the result of the preceding experiments. Decapsulation combined 

 with obstruction produces a greater distension of the tubules than obstruction 

 alone. With a more abundant diuresis than occurred in this experiment a 

 similar result is found in the capsules and glomeruli. 



In the following tables we collect the results obtained in our thirteen 

 experiments. In the first we give the means of the approximate volumes 

 of Bowman's capsule, glomerulus and fluid, and in the second the ratios of 

 these to the similar structures in the resting kidney. 



We would not lay much stress upon comparisons between these figures, 

 except when the differences are very marked. There are so many varying 

 factors upon which the actual magnitudes of the measurements depend that 

 to do so would lead to erroneous conclusions. Thus, the results vary with 

 the blood-pressure, with the degree of diuresis established, the duration of 

 the diuresis, and especially with the degree of extensibility of the kidney 

 Capsule, and of the general renal tissues, both of which we know to vary 

 greatly in different animals. Table II, however, shows very decisively the 

 enormous changes in size of the glomerulus and capsule caused by active 

 secretion of water, and more especially in the very great accumulation of 

 water within the capsule during activity. All these results are of the 

 highest importance in disproving the possibility of filtration at the glomerular 

 surface. 



