ON THE SUPRARENAL BODIES OF YERTEBRATA. 137 
On the Suprarenal Bodies of Vertebrata. 
By 
W. F. R. Weldon, B.A.. 
Fellow of St. John’s College, Cambridge; Lecturer on Invertebrate 
Morphology in the University. 
With Plates XI and XII. 
The suprarenal bodies of Vertebrates are, as is well known, 
made up of two sets of elements, sharply distinguished from 
one another, both by their adult structure, and by their mode 
of origin in the embryo. The substance which from its posi- 
tion in the mammalian suprarenal is known as “ medullary ” is 
now almost universally admitted to consist of metamorphosed 
nerve-cells, which arise from one or more of the ganglia of 
the sympathetic system. As to the origin of the remainder, 
however, the so-called “ cortical ” substance, little is certainly 
known. In Elasmobranchs, Balfour 1 describes the homologue 
of this substance as “ making its appearance . . . as a rod-like 
aggregate of mesoblast cells, rather more closely packed than 
their neighbours, between the two kidneys near their hinder 
ends ; ” but he leaves it an open question, whether these cells 
arise from the general indifferent mesoblast surrounding them, 
or whether they are derived from any of the adjacent organs 
of the embryo. 
These observations of Balfour were followed, in 1882, by two 
1 “ Elasmobranch Fishes,” p. 246. 
