239 
Turning next to the bodies described by RATHKE, we found on 
dissecting away the black pigmented tissue, covering the posterior 
cardinal sinuses, that on the walls of these two sinuses immediately 
posterior to the pericardium, was a series of small yellowish-grey 
bodies, almost exactly as described by RATHKE. They are scattered 
irregulary on either side in little clusters or groups. RATHkE’s figure !) 
which we here reproduce is of a young Petromyzon and the bodies 
are rather larger than those in the adult. These bodies have not 
previously been described in the adult. 
In another specimen, where these 
bodies were exceedingly minute, a 
somewhat large oval-shaped body was 
found, between the dorsal wall of the 
sinus venosus and the ventral wall of 
the dorsal aorta, this was larger and 
whiter than the largest of the bodies 
met within any of our dissections from 
the walls of the posterior cardinal 
sinuses; its greatest length measuring 
3—D mm. 
RATHKE ?) makes mention of some 
bullet-shaped bodies, which we also 
found. There can be little doubt but 
that these are similar in all respects, 
excepting size, to the ,,white-bodies”’. 
When examined more carefully, all the 
bodies mentioned by RATHKE, and the 
larger oval-shaped body we have found, 
appeared yellowish-grey or white. To 
Fig. 2. The anterior portion of Petromyzon (after Ratuke). / Fat bodies; 
in intestine; & kidney; t testis; w. s. ‘‘white-specks”. 
the naked eye they certainly resemble the suprarenal bodies of a 
small Teleostean fish, When examined histologically, however, their 
true structure is shown to be connective tissue. Under a low power 
they appear as if they might be glandular, as they are rounded, and 
contain nuclei scattered through their substance, but a high power 
reveals the fact that they consist of fibrous tissue, and nucleated 
1) Op. eit., Tab. 11, Fig. 8. 
2) ‘Op. J citi 99 
