CHONDROCRANIUM OF EUMECES 163 
Crocodilia. The only question is whether this union is primitive 
or secondary. Only in Sphenodon is the union persistent; in 
most forms it is of very early appearance and disappearance— 
blastema stage in Testudo (Bender, 711); blastema (Cords, ’09) 
or procartilage (Fuchs, ’07 a) in Lacerta; procartilage in Eumeces. 
In general, too, as in Eumeces, the course of development is 
from complete connection to complete separation. The general 
occurrence of this connection through the reptilian series, its 
early ontogenetic appearance, and its later disappearance speak 
strongly for its primitive character and make very probable the 
hyoid relationship of the hyostapes. 
Is the otostapes genetically related to the otic capsule? That the 
footplate of the columella and the wall of the otic capsule are 
in very close union (although usually distinguishable) in early 
stages of many reptiles is conceded by the supporters of the view 
that the entire columella is of hyoid origin—Schauinsland (’00) 
and Howes and Swinnerton (’01) for Sphenodon; Versluys (’03) 
for Lacerta and Hemidactylus; Cords (’09) for Lacerta; Shiino 
(14) for Crocodilus. On the other hand, in Platydactylus and 
Gecko (Versluys, 03) and Testudo (Bender, ’11, ’12) the anlage 
of the footplate is described as conspicuously distinct from the 
otic capsule. In the blastema (Platydactylus and Gecko) or 
even the cartilage stage (Testudo) the otic capsule is said to be 
completely closed median to, and independently of, the foot- 
plate; the fenestra vestibuli arises by a resorption of the tissue 
of this complete capsular wall. In the geckos Fuchs (’09) has 
confirmed this distinctness of the anlage of the columella, which 
he considers a precocious development, due, perhaps, to its 
perforation by the stapedial artery. Eumeces conforms clearly 
to the first of these types of development. In stage 1 the foot- 
plate of the columella is undoubtedly confluent with the sur- 
rounding tissue of the capsular wall, although there is a slight 
histological difference. The columella may perhaps be char- 
acterized as procartilage and the surrounding tissue as blastema, 
but the difference is slight and the transition a very gradual one. 
Moreover, the superficial parts of the stalk of the columella show 
