STRUCTURE AND DEVELOPMENT OF REISSNEr’s FIBRE. 39 
Text-fig. 3. 
A 
tct.mes. 
Slightly diagi'ammatic transverse sections through the anterior 
portion of the inicl-brain of (A) Scyllium canicnla; (b) 
Acipenser sp. ; (c) Esoxlucius; to show the relations of 
the cells of the "Dachkern” to the Tectum mesencephali, 
Recessus niesoccelicus, and posterior commissure, [(b) is 
Lon-owed from Johnston's work on the brain of Acipenser (’Ol). 
A and C ai-e taken at levels indicated by the lines ««' and cc in 
Text-fig. 2, A and E.] X<A:. “ Dachkern.'’ iter. Itev. Meso- 
coelic recess, op. Optocoel. p.c. Posterior commissure, s.c.o. 
Sub-commissural organ, tct. mes. Tectum mesencephali. 
