166 EDWARD L. RICE 
the otic character of the amphibian operculum. All things 
considered, the otic relationship of the otostapes appears more 
probable than its independence of the auditory capsule. 
Are otostapes and hyostapes genetically related to one another? 
I discuss this question independently of the answers given to 
the two preceding questions. In stages 3 to 6 of Eumeces the 
columella is an unquestionably continuous mass of cartilage; 
but in each of these stages there is equally unquestionably one 
zone in which the cartilage shows a slightly more embryonic 
structure—smaller nuclei and less of matrix. This zone, which 
I interpret as the junction of otostapes and hyostapes, corre- 
sponds with the constriction already mentioned between the 
processus internus and the insertion plate. This is the position 
assigned to this junction by Versluys, but not by Fuchs (see 
also p. 162). In stage 2 this zone of junction is procartilaginous 
rather than cartilaginous, although the balance of the columella 
has reached the condition of unquestionable cartilage. This 
is the stage of maximum distinctness of otostapes and hyostapes. 
In the still younger stage 1 the entire columella is composed of 
procartilage and no differentiation of the parts is recognizable. 
This appears to be the usual rule for the development of the 
columella—an originally continuous anlage, which becomes di- 
vided for a very brief period at the beginning of chondrification. 
Only in Lacerta, as described by Fuchs (’07 a), do I find a differ- 
ent succession of events recorded—a division in the blastema 
stage preceding the continuity of the procartilage. This is not 
recorded by other workers on Lacerta, and for Emys, Fuchs 
himself gives a description apparently consistent with the above 
account of Eumeces. The preponderance of evidence strongly 
favors the interpretation of the columella as a unit structure, 
with otostapes and hyostapes in direct genetic relation to one 
another. 
Are the above conclusions consistent? The conclusions that the 
hyostapes is genétically related to the hyoid arch, that the 
otostapes is genetically related to the otic capsule, and that the 
otostapes and hyostapes are genetically related to one another 
are apparently hopelessly contradictory; I believe that a further 
