446 Reptilian Epiphyses 
hatching and subsequent stages. In none of the specimens, although I 
have examined them with the greatest care, have I been able to find the 
slightest indication of bony epiphyses on any of the skeletal elements. 
The embryo turtles, when cleared, show the ossificatory centers of the 
bones very beautifully, but there is never any separate center for an 
epiphysis. If epiphyses are to be found in the turtles they should be 
present in the young animal. In a specimen of Chelydra serpentina 
Linné, 44 mm. in length, the limb bones (Fig. 1) show no differences 
from the limb bones of an adult Chelydra excepting, of course, in size. 
We should certainly expect epiphyses to be evident at this stage, if ever. 
They are not present in a slightly younger specimen of Chelydra, nor are 
there any evidences of them in a more advanced Chrysemys. 
Smith Woodward (5) states: ‘ Other characters, such as the conical 
epiphyses of certain limb bones, also seem to imply community of origin 
of the Chelonia with the Sauropterygia and Batrachia”; and Parsons (6) 
states in parenthesis: “ I think that I have found traces of an epiphysial 
line in the great trochanter of the Chelonia, but am not sure of it.” The 
“ conical epiphyses of certain limb bones ” were first noted by Seeley (21) 
in his essay on Pariasuarus where he says: “ All the long bones of the 
Nothosauria and Plesiosauria ossify in the same way as the long bones of 
living frogs, and consist of cylindrical girdles into which long, conical 
epiphyses penetrate, so as to meet, or nearly meet, in the middle of the 
shaft, from which they are often easily or naturally separated. I have 
had no opportunity of determining whether this condition is present in 
the long bones of Labyrinthodonts, and I only otherwise know it as a rare 
condition in some of the long bones of Chelonia from the Cambridge 
Greensand, and in an undescribed epiphysis, which I believe to be Dino- 
saurian, from the Oxford Clay, and the proximal end of the tibia of 
Protorosaurus.”’ In his essay on Protorosaurus Seeley (22) practically 
repeats the same facts. 
From the above quotation it is evident that Seeley had a correct idea of 
the ossification of the reptilian bones. The term epiphyses was used, it 
seems to me, inadvertantly to express the nature of the elements and not 
to express the idea of any homology of the reptilian structure with the ~ 
familiar elements in the mammals. Later authors following Seeley quoted 
his words but missed the idea and hence has arisen the present discussion. 
Osborn (23) mentions epiphyses as possible evidences of relationship 
between the turtles and plesiosaurs. The fact remains, however, that 
there is not the slightest evidence either embryologically or anatomically 
of any bony epiphyses on any of the skeletal elements of the Chelonia that 
