VIII Proceedings of the Association of American Anatomists 
ternus in the embryo measuring 12 cm. in length. In the embryo 15 em. 
long processes had formed from the cells throughout the coils of the 
cochlea and the bunching up of the cells in the sulcus externus began to 
appear preliminary to the actual invasion of the spiral ligament by these 
cells. In the foetus at full term groups of these epithelial cells from the 
sulcus externus had invaded the spiral hgament, especially in the basal 
coil, to such an extent that their nuclei were found buried in the spiral 
ligament as deep as midway between the sulcus externus.and the osseous 
capsule, while protoplasmic process from these cells could be traced out 
to the loosely arranged connective tissue of the spiral ligament lying 
next to the osseous capsule. 
In sections cut parallel to the coils of the cochlea a continuous line of 
these cell groups would be found. These groups were arranged at regu- 
lar intervals, and it was noted that the free surface of the epithelium in 
the sulcus externus showed a distinct depression marking the site where 
each group of cells penetrated the spiral hgament. A close study of these 
cell groups showed that where the section cut such a group through the 
center of its axis a small but distinct duct could be distinguished. Per- 
pendicular sections cut through the edge of the cochlea would often cut 
these cell groups at right angles. In such sections it was noted that these 
cells were usually slightly separated from the surrounding connective 
tissue probably due to shrinking. In these sections the central duct could 
often be made out. 
THE NERVE SUPPLY TO THE LEG OF THE FROG AFTER COMPLETE 
DEGENERATION OF THE MOTOR FIBERS. By ELizasetH H. DUNN. 
Department of Neurology, University of Chicago. 
After severing the anterior roots of the 8th, 9th, and 10th left spinal 
nerves (Gaupp’s nomenclature) in a frog, Rana virescens Cope; female, 
length 229 mm., weight about 55 grams, a period of eight months was 
allowed for the completion of degeneration. On comparison of the osmic 
stained nerves at various levels the following conclusions seem justified. 
A large afferent suply to the muscles, about 50% of the total normal 
supply, is present at all levels. 
On each side the findings as to the size of the largest fibers innervating 
the various segments corroborate the earlier statement that the largest 
fibers run the shortest distance, a marked diminution appearing in the 
average areas of the largest fibers given off. successively to the thigh, 
shank, and foot. 
A comparison of the muscular and cutaneous afferent fibers as to size 
shows that the largest are distributed somewhat evenly in both instances, 
but that many more very small fibers pass to the skin than to the muscles. 
