548 
of the development of the reptilian columella is especially desirable. 
Although the turtles represent in this respect an aberrant group of 
reptiles, nervertheless a fuller knowledge of their line of specialization 
may be of service in unravelling the complexities of the broader 
problem. 
In spite of the fact that the structure of the adult columella has 
been variously described by a number of the earlier investigators, 
for example MOLDENHAUER, BOJANUS, RATHKE, PETERS, and AGAssız, 
its development has been touched upon by one only, PARKER.!) 
In studying the green turtle, Chelone viridis, he believed that the 
columella originated in two parts; the operculum (base) from the otic 
capsule, and the other, composed of the medial stapedial element 
(shaft of the columella) and an insertional disk (extra-columella) 
from the hyoid arch. 
Within the last few years the problem has been worked upon in 
other forms. In 1907 two investigators, Noack?) and Fucus,?) 
studied Emys europaea. Fucus’ general conclusions are not unlike 
PARKER'S; he also thought that the columella originated in two parts, 
each from a different source, the extra-columella from the hyoid arch 
and the columella proper from the ear capsule. In the following 
discussion Fucus’ work is disregarded on BENnDER’s authority that 
his results were based on a single series which, of course, is not 
adequate in a developmental study. 
Noack did a more extensive piece of work; he traced the devel- 
opment of the entire sound-transmitting apparatus and holds that 
the columella originates as a single element from the otic capsule, 
and at no time has any connection with the hyoid arch. 
In 1911 Kunxet‘) made a brief statement concerning the devel- 
opment of the columella of Emys. He shares Fucus’ opinion of its 
compound origin. 
1) PARKER, W. K. 1880. Report on the development, of the green turtle 
(Chelone viridis). Report on scientific results of the Voyage of H. M. S. «Challengers 
during the years 1875—76. Zoology, 1. 
2) Noack. 1907. Uber die Entwickelung des Mittelohres von Emys europaea 
nebst Bemerkungen zur Neurologie dieser Schildkröte. Arch. f. mikrosk. Anat., 69. 
3) Fucus, H. 1907. Uber die Entwickelung des Operculums der Urodelen 
una des Distelidiums (Columella auris) einiger Reptilien. Anat. Anz. Ergänzungs- 
heft, 30. 
4) Kunker, B. W. 1911. Zur Entwickelungsgeschichte und vergleichenden 
Morphologie des Schildkrötenschädels. Anat. Anz.; 39, p. 362. 

