THE EPIPHYSIS OF TELEOSTS AND AMIA! 
CHARLES HILL. 
Previous to 1882 our knowledge of the epiphysis in fishes 
was limited to the brief notices of Cuvier (05), Carus (14), 
Gottsche (35), Stannius ('54) and others, who content them- 
selves with references to its existence and macroscopic appear- 
ance. Cattie (82) carefully describes the external features 
of the organ in adult Teleosts, Plagiostomes and Ganoids, 
and speaks in some detail of its histological structure. he 
consists of a granular matrix in which are embedded round, 
pear-shaped or bipolar cells, the processes of which anastomose 
with those of neighboring cells. 
Rabl-Riickhard (82) gives a detailed description of the early 
stages in the development of the epiphysis in Salmo salar and 
Salmo fario, and also shows by figures the development of the 
organ in embryos between 3.5 mm. and 22.5 mm. in length. 
Its history in embryos longer than 22.5 mm. does not appear 
to be known. 
During the last ten years the attention of morphologists has 
been turned to the epiphysis in Petromyzon and Reptilia to 
the exclusion of nearly all other forms. Hoffmann (’85) in a 
paper on the development of Reptilia records an observation 
on the development of the epiphysis in Salmo salar and 
Salmo fario to which I shall refer in another part of this 
paper. 
This work was begun at the suggestion of Professor J. E. 
Reighard with the purpose of completing the history of the 
development of the epiphysis in Teleosts, and of establishing 
as accurately as possible its adult histological structure. 
1 Work from the Morphological Laboratory of the University of Michigan, 
under the direction of Prof. J. E. Reighard, accepted as a thesis for the degree of 
Master of Science. 
