552 
eonsideration, the above mentioned condensation cannot be the 
erista parotica because it is in the ventral, not dorsal, region of the 
capsule. Whether it simply represents a portion of the capsule which 
is forming more rapidly than the rest, or whether it is, as, was first 
supposed, the proton of the basal part of the columella is difficult 
to determine. There is no actual connection between this condensation 
and the more lateral one, representing a part of the whole of the 
columella, although there is a faint. indication of loose strands 
of cells stretching out toward it. In slightly older embryos, behind 
the hyomandibular arch, the proton of the entire columella, a con- 
tinuous condensation stretching out laterally from the capsule to 
close under the surface ectoderm, is unmistakable (Fig. 4). It is 
true, moreover, that in 
y this embryo, the base of 
a hie: the columella is well 
marked off from the cap- 
sule. As BENDER has 


Ivc.-$ Be 8 . i f ER x eRe 
pexcol. fe : eter 3 - ca pointed out, if im these 
i =e — P.S.cO 
2 a rr ; early stages the base of 
vc tae -P.b.co 
: the columella is distinct 
v.ci.-$ EA from the surrounding cap- 
HL. f oa sula, it is good evidence 
-q-mlab that it is not of capsule 
origin. Furthermore, he 
has called attention to the 
Fig. 4. Section of another embryo of the same fact that although Noack 
measurement, but slightly older. f.c. hyoid cornu; and Fucus claim a cap- 
p-b.col. proton of base of columella; p.s.col. proton sular origin for a part 
of shaft of columella; v.c.l. vena capitis lateralis. 
Other abbreviations the same as before. (Fucus), or the whole 
(Noack) of the columella, 
they neither describe nor figure any stage in which its base is not 
distinguishable from the capsule. In view of this and BENDER’s own 
work on Testudo graeca, at the present time the writer is inclined to 
believe that there is probably no element of capsular origin in the 
columella of Chrysemys marginata. 
To consider the nerves and blood vessels of the ear region in this 
earliest stage, we find on the median side of the condensation of the 
otic capsule the common ganglion of the N. acusticus and N. facialis. 
in the form of a short, thick strand of fibers, the N. facialis leaves 
