402 The Arteriolae Recte of the Mammalian Kidney 
preparations of the rat’s kidney, I am able to confirm the observation 
made by Golubew that the efferent glomerular branches which form the 
arteriole rect give off side branches which form capillary networks at 
the level of the base of the renal pyramid. Such side branches of the 
efferent glomerular vessels destined to form arteriole rectee I have ob- 
served also in the kidneys of the other animals studied, though they are 
not nearly so numerous as in the white rat. So far as may be determined 
in corrosion preparations in which the peripheral portions of the inter- 
lobular arteries appeared completely injected, these end in afferent 
glomerular branches and do not present terminal branches which end 
directly in capillaries in the peripheral portion of the renal cortex. Now 
and then, and more particularly in the dog, have I found an interlobular 
branch which did not completely break up into branches within the renal 
cortex, but could be traced beyond the outer border of the cortex 
anastomosing, as would appear, with capsular branches. Afferent glom- 
erular branches arise from such interlobular branches to near the per- 
ipheral part of the cortex. The question may be asked whether the 
“arteria capsularis glomerulifera” described by Golubew may not pe 
interlobular arteries of the above type imperfectly injected from the out- 
side. As I have not attempted corrosion injection through the aorta after 
tying the renal arteries, I am not able to decide this point. 
In this account, no mention has been made of observations on the 
human kidney with reference to the points more particularly under dis- 
cussion. The limited human material at my disposal has not been fresh 
enough to enable capillary injection with subsequent corrosion by the 
method used. In the attempts made the injection mass could readily be 
forced into the glomeruli, but only to a limited extent into the efferent 
glomerular vessels, as a rupture of the glomerular vessels in many places 
allowed its escape into the space enclosed by Bowman’s capsule and then 
into the uriniferous tubules in which it would pass to about the begin- 
ning of the descending limb of the loop of Henle, giving excellent and 
instructive corrosions of the proximal convoluted portions of the urinifer- 
ous tubules. Similar observations were made on injecting through the 
renal vessels of the kidneys of animals several hours after death. It is 
hoped that this method may prove useful in the hands of others with 
access to fresh human material in determining the origin of the arteriole 
recte and the existence or non-existence of terminal arterial branches not 
directly associated with glomeruli. 
From observations made on corrosion preparations of the dog, cat, 
rabbit, guinea pig, and rat, in which it is possible to trace the renal 
