180 Journal of the Asiatic Society of Bengal. [N.S., XVIII, 
crease in chloride strength is less marked than in Experiments 2 and 
Similar comparison of chloride strengths in Experiments 7-10 ¢ 
firms this explanation. Thus in Experiments 8, 9, 10 (veins at first ones 
the average chloride strength of ‘‘ open vein’ urine was 0°005077 gm. 
akay samples) ; 
and ap  * sub vein 5, at 0:005334 gm. 
(three » samples) 
and in Experime 
pe 
the shiehie strength of * ae vein ° > urine was 0:005627 gm. 
open 0°005899 gm. 
The ie nen - Secaah batven ge ‘open vein ”’ and ‘‘ shut vein” 
urines of Experiments 8, 9,1 s 0000272 gm., and that of Experiment 
7 was 0:000257 gm., these fo ec therefore being eaotialle equal. 
oe conclude from these sige that the presence or ab- 
sence of the kidney venous supply makes eee to the chloride 
strength ot the rape excreted, a con a exo = have already loa 
from the toad experiments descri bed in Part II, and which will be 
ther confirmed by the pene of experiments on the Mola frog dese vibed 
in Part IIT. This conclusion however is opposed to that of Bamnbedee, 
Collins and — tts p. 359) who maintain that ‘‘ ‘ the urine obtained on 
a simultaneo al and venous perfusion does not, "9 far as we could 
e more conducive to the formatio y dilu tel. eee gtr is 
arterial perfusion alone.”’2 It is impossible “ae me to arte what I 
consider to esis parodies. gaat the experiments of t authors 
(and they quote no experi s at all. similar to those I ies ‘aseccthe d) 
b »ecause, from my PRE rs oe (as well as those of their later paper, 5 
are nearly all vitiated by the idea that the renal afferent veins supply 
the kidney tubules, and f demur entirely to each assumptions that, e 
used wi Ol nly the 
these 
sesh Page of the nevessity.. jet maintaining correct relative flows and 
i pressures in the renal afferent veins and aorta, and on this 
pons unt alone most of the. results given are devoid of value from the 
nesta point of vie 
APPENDIX F. 
Mode of Preparation of ‘ Poli pie a le eaneeron of Gurwitsch’s 
(V.B.—The following ie also applies, with modifications, to - 
nts - 
the preparation of frogs for the perfusion experiments per 
formed by me.) 
The frog (alwa ays a male, so avoiding the oviducal veins, oviducts 
and — ovaries) is first deeply anaesthetized with ether, and, when 
' My italics. The term ‘‘ dilute” here refers to sodium chloride, 
the os hopes constituent 
ti 

not. 
= is that = and water usually go ‘together, i, a Bescon a 
eak in salt, it is also relatively strong in nitrogen, or, in other 2 words, 
Salieiee i in aekee (see Appendix G, Part III). 

Bree it Nr NOG EN ple ROR IGE AES OES SESS es alae SO ee Sit en ah ae ST eeeate ett 7? SI 



