438 PROCEEDINGS OF THE CANADIAN INSTITUTE. 
independent manner. The form varies from round to oval, and the 
size ranges from 1 mm. to nearly 3 mm. through the long diameter. 
The suprarenal bodies are separated from the substance of the 
kidney in which they lie not only by their own capsule but also by 
that of the kidney, the two being however united as one throughout 
almost the whole extent of surface lying in contact. This double 
wall does not measure more than 10°8y at the thickest part. As 
mentioned above, it sends in at various points processes in which the 
stems of the blood-vessels run. 
The interior of the organ is made up of lobules or alveoli, each 
one being enclosed in a delicate but distinct fibrous capsule joined to 
those adjacent so as only to appear distinct in certain angles. This 
partition wall does not average more than 1*5 y in thickness, The 
lobules are more or less oblong in form, from 26-4 to 66:2 » thick 
and 200 » as greatest length. The diameter varies in the same 
lobule, and they are frequently bent upon themselves at one end. 
No part of the body is marked off from the rest either by the form, 
size, or arrangement of the lobules. If these correspond to the 
divisions of the cortex in the suprarenal of higher vertebrates the 
medullary portion is entirely absent. 
The contents of the alveoli are granular nucleated cells of varying 
form and size (Pl. VIII. Fig. 11), the longest being nearly 40 » and 
frequently reaching from wall to wall. After studying a number of 
sections, I am forced to the conclusion that the large and the small 
cells have no fixed relations. 
Some alveoli appear to be composed entirely of long cells arranged 
parallel to one another, with spaces between their outer pointed 
ends ; others show an almost homogeneous granular matrix contain- 
ing nuclei, the limits of whose cells can rarely be detined. A com- 
bination of these is the commonest arrangement, where the long cells 
being arranged as before with the axis at right angles to the long axis 
of the alveolus, the smaller cells are fitted in between. A compara- 
tively regular row of nuclei around the margin gives in many 
instances the appearance of a lumen and epithelial lining, especially 
in teased preparations, but in section the true structure is easily dis- 
cerned. 
In the alveoli of the lateral portion of the body, where the cell 
limits were least defined, a number of small round, oval or triangular 
cells were distributed, principally upon the margin, (Pl. VIII. Fig. 
