REPTILIAN EPIPHYSES. 
BY 
ROY L. MOODIE. 
From The University of Chicago. 
WiTH 24 TExT FIGURES. 
It has long been the opinion of anatomists that bony epiphyses are 
confined exclusively to the skeleton of the Mammalia. Among other 
features often given as characteristic of the mammals is the one that 
epiphyses occur on the bones. 
Dollo (1) in 1884 first called attention to the fact that real epiphyses 
are found in the reptiles, although Albrecht (2) had the year before pub- 
lished a short note on epiphysial structures of the vertebral spines of 
Sphenodon. Dollo gave a complete summary of the literature on the 
subject and a list of epiphyses which he observed in seven families of the 
lizards and in Sphenodon. He promised a more complete description with 
illustrations but I have not been able to ascertain that his promise has 
been fulfilled. Parsons (3) writing twenty-two years later, has revived 
the interest in epiphyses of the reptiles in connection with his studies on 
the epiphyses of the human skeleton. 
At the suggestion of Dr. Williston the study of epiphyses as they occur 
in the reptiles was taken up in an attempt to solve the problem of the 
relationship of the Chelonia and Plesiosauria as evidenced in the so-called 
epiphyses of the two groups. The methods pursued are those referred to 
in a previous contribution on the lizard sacrum (4) and which are given 
below in full. These methods of clearing animal tissues were first intro- 
duced into America by Dr. Mall and were first fully outlined by him in 
his study of ossification centers in the human embryo (17). Hill (18) 
further outlined the methods and gave their application to subjects other 
than the study of osteology. The method consists principally in the 
use of KOH as a clearing agent on objects too large for the ordinary 
clearing agents to act upon. This was the method pursued by Schultze 
(20) who was its originator, and it is usually known as the Schultze 
method. 
AMERICAN JOURNAL OF ANATOMY.—VOL. VII. 
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