Medullary Loop of the Renal Tubule of Mammalia. 95 
the pancreas of the dog. We have, however, from our experiments 
no evidence to show that the prostration and collapse of acute 
pancreatic disease are caused by the absorption and effect on the 
blood pressure of the unaltered pancreatic juice or the products 
of the earlier stages of autolysis. The part played by autolysis 
in the production of further depressor and toxic substances and 
especially the part played by the activation of the pancreatic 
secretion by the enterokinase, which body presumably finds en- 
trance into the organ in the development of the human lesion, 
are phases of the subject which we now are investigating. 
57 (582) 
The significance of the structure of the medullary loop of the 
renal tubule of mammalia. 
By G. GAUL HUBER. 
[Laboratory of Histology and Embryology , University of Michigan.] 
A method of maceration has been devised recently 1 by means of 
which it is possible to isolate the entire renal tubule of adult mam- 
mals. Certain of the renal tubules thus isolated have been stained 
and permanently mounted in glycerine. This enables a study of 
their form in a manner hitherto not possible and admits of an 
accurate determination of their epithelial lining. Each mam- 
malian renal tubule possesses four types of epithelium: (1) The 
pavement epithelium surrounding the glomerulus and lining the 
glomerular capsule; (2) the specific renal epithelium of the proximal 
convoluted portion and its medullary segment; (3) the pavement 
epithelium of the medullary loop; (4) the cubic or short columnar 
epithelium of the ascending or distal arm of the medullary loop 
and the distal convoluted portion. The following table shows 
the distribution of the last three types of epithelium in renal tubules 
of the rabbit, the tubules selected representing A, a tubule with 
renal corpuscle situated at the periphery of the cortex; B, a tubule 
with renal corpuscle situated in the deeper portion of the outer 
half of the cortex; C, a tubule the renal corpuscle of which is situ- 
ated in the deepest part of the cortex. 
1 G. Carl Huber, "A method for isolating the renal tubules of mammalia," Anat. 
Record., v., April, 191 1, 
