X Proceedings of the Association of American Anatomists 
ing that these folds not only are associated with serial nerve roots, but 
with the longitudinal association tracts. 
From the above it seems probable that segmental relations in the adult 
brain can ultimately be traced with greater accuracy than hitherto. 
THE ORIGIN OF THE GERM CELLS OF THE TURTLE. By BENNET M. 
ALLEN. Department of Anatomy, University of Wisconsin. 
EARLY STAGES IN THE DEVELOPMENT OF THE NASAL SKELETON 
OF AMBLYSTOMA. By Roserr J. Terry. Washington University, 
St.-Louis. 
THE MUSCLES OF THE FEMALE PELVIC FLOOR. By WrriLiAm KEILLer. 
Medical Department, University of Texas, Galveston. 
Read by title. 
THE FIFTH AND SIXTH AORTIC ARCHES AND THE RELATED PHAR- 
YNGIAL POUCHES IN THE RABBIT AND THE PIG. By FReEpERrIc T. 
Lewis. Harvard Embryological Laboratory. Presented by Charles 
S. Minot. 
FURTHER EXPERIMENTS ON THE DEVELOPMENT OF THE PERIPHER- 
AL NERVES OF VERTEBRATES. By Ross G. Harrison. Depart- 
ment of Anatomy, Johns Hopkins University. AMERICAN JOURNAL OF 
ANATOMY, VOL. V. 
EXPERIMENTAL EVIDENCE IN SUPPORT OF THE OUTGROWTH 
THEORY OF THE AXIS CYLINDER. By Warren Harmon LEwIs. 
Associate Professor of Anatomy, Johns Hopkins University. 
The nasal pit in amblystoma when transplanted, at a stage before its 
nerves appear, in such a manner that its deep surface lies in contact with 
the inner layer of the ectoderm, will send out its nerve fibers between 
it and the ectoderm at which place there is no mesenchyme. 
If the anterior end of the brain is removed before the olfactory nerves 
are sent out, mesenchyme fills in the region more or less and the nerves 
from the nasal pit grow out into this mesenchyme in various directions, 
and as in the transplanted pit they take paths which are in no sense pre- 
determined. 
The optic nerve from transplanted eyes, in the majority of instances, 
runs for long distances in among the pigment cells of the outer layer. 
In a few experiments where the transplanted eye is in contact with the 
medulla, the optic nerve may pass into the medulla and run for some 
distance in the latter. In a few instances the fibers of the optic nerve 
pass directly out through the pupil into the mesenchyme surrounding the 
transplanted eye. 
