BLOOD-VASCULAR SYSTEM, ETC., OF AMIURUS CATUS. 439 
11, B). » They stain deeply and evenly throughout like the nuclei of 
the blood cells or the nucleoli of the ordinary suprarenal cells, but 
are larger and more irregular inform. They are most probably small 
ganglion cells. 
The blood-vessels of the bodies are small and the capillaries do not 
seem to be abundant, which explains their pale color. The blood 
supply seems no more than sufficient for the nourishment of funce- 
tionally active organs of their size.* Mr. Weldon’ lately suggested 
that these bodies are probably related to the kidney and perform 
some function in connection with the elaboration of the blood. 
My observations upon Amiwrus, although imperfect, are opposed to 
such conclusions. The smallness of the blood supply, the absence 
of ducts and of all stored up remains of its action, such as the 
brown pigment of the kidney, head-kidney and spleen, or the colloid 
matter of the thyroid, and also its structure, mark it off from the 
other blood-glands. He further remarks: “ In Teleostei supra- 
renals are at all events frequently absent; or, as I would rather 
suggest, they are represented by the greatly metamorphosed head- 
kidney described by Balfour. In other cases where suprarenals have 
been detected, they have always been attached to the surface of 
the kidney.” In regard to the first point, we have in the cat-fish a 
well developed head-kidney in which the metamorphosis can be 
traced and which preserves its relation to the renal-portal system, 
and presents the characteristics of a blood-gland. The position upon 
the surface of the kidney is no doubt due to the development of the 
latter causing it to press upon the body and carry it outward upon 
its surface. It is certainly neither connected with the kidney nor 
yet with its blood-vascular system in the adult, whatever may be its 
developmental relationships. 
Certain other gland-like structures are attached to the walls of the 
veins in the body cavity. They were observed in sections of the 
head-kidney surrounding the cardinal vein, but are specially abundant 
--on the portal vein between the spleen and the liver. They are 
small white bodies varying in size and form, sometimes appearing 
small and rounded upon the side of the vessel, sometimes forming a 
* Norr.—In teased preparations the blood cells bear a very small proportion to the other cells. 
1 Quart. Jour. Mic. Sc., N.S., Vol. XXIV., p. 176. 
