238 
Myxine glutinosa. 
After a careful examination of the renal organs and in the region 
where the “white bodies” of RATHkKE are found in Petromyzon, 
we failed to find any similar structures. 
Petromyzon marinus. 
An examination of adult specimens was first made. The kidney 
was carefully dissected, and searched through for any structures corre- 
sponding to suprarenal bodies, but none were found. Microscopical 
preparations were next made of the anterior portion of the kidney, 
here the normal kidney structure obtained, there being nothing corre- 
sponding to the lymphatic head-kidney of Teleosts. 
The triangular bodies described by Ecker!) seemed from the 
first to be but connective tissue. They lie on the inner wall of each 
posterior cardinal sinus, on either side of the vertebral column. They 
commence immediately behind the pericardium, posteriorly they be- 
come smaller and in some cases they were observed to be broken up 
into a series of almost disconnected 
patches. We failed to trace any openings 
£ ee 2 on the upper surface, for the passage 
n.ca | = of blood-vessels, as described by ECKER. 
eg Each body when dissected out was 
SS (ne, of firm consistence, of a light mottled- 
ee fA grey colour, and its naked eye appearance 
cb. Ee) hie did not at all favour the likelehood of 
/ AST “ its being of a glandular nature. When 
N y hardened in alcohol, stained with haema- 
ae hk toxylin and cut, after being imbedded 
LA : Boe sh in paraffin, no trace of glandular struc- 
uw Vy oO y ture was visible. It consists of a con- 
NG N nective tissue meshwork with branched 
Fig, 1. Transverse section through Petromyzon marinus showing position 
of EcKERr’s bodies. 
E. 6, EckeEr’s body; / t fibrous tissue; i intestine; % kidney; ly sub-vertebral 
lymph spaces; n. ca. neural canal; nc notochord; p. c. s. posterior cardinal sinus; 
t testis; ur ureter. 
nucleated cells and their processes. In some places the cells had 
the appearance of having contained fat, which had been removed by 
the process of preparation. This tissue is probably an embryonic 
connective tissue, the forerunner of a part of the vertebral column ; 
possibly it may represent an osteogenetic. tissue. 
1) Op. cit., p. 32. 
