220 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
pass upward between the sense cells. At their terminations they turn 
backward, forming a loop. A far greater number of fibres, however, 
are described as passing to the bases of the sense cells, where the 
fibrillae separate from one another and appear to clasp the cells as a 
bird’s claw clasps a ball. This appearance, however, they believe to 
be due to incomplete impregnation. Cases are described in which only 
a few fibrillae are stained; these attach themselves to the surface of the 
cell, but can be followed only to the level of the upper surface of the 
nucleus. Besides these, they reproduce structures in which the whole 
cell body is enwrapped in the finest terminal twigs, which appear to be 
bound together by delicate anastomoses. Finally, cells are frequently 
found which are enclosed from base to periphery with a close-meshed 
trestle-work of larger and smaller fibrillae. They believe that these 
different appearances are due, not to the existence of different modes of 
termination, but rather to differences in the completeness of impregna- 
tion, and that the more numerous and more simple structures are 
incompletely impregnated, and that the rarer pericellular networks 
represent the universal terminal structure. I take it that they regard 
this structure as identical with the terminal expansion which has been 
referred to as a calyx structure. It is declared that the pericellular end 
structures, described by Ramén y Cajal as restricted to the summits 
of the cristae, have been found by them in all parts of the cristae, and 
are abundant in the maculae as well. Occasional sense cells are found 
which contain within them a definite ring-shaped body, stained like 
the axis cylinders. ‘The microchemical behavior of this body leads 
these investigators to regard it as nervous in character. Examples 
were found in which this endocellular ring was connected with the 
pericellular network by a fibrillar bridge. The authors believe that 
in this structure they have found an altogether unique end-organ within 
the sense cell. They suggest the probability that this structure acts 
as a transporting mechanism which communicates the movements of 
the protoplasm of the sense cell to the fibrillae lying on its outer surface. 
The relation between sense cell and axis cylinder is not in their opinion 
one of contact; they prefer to describe it as one of concrescence. In 
the hope of being able to ascertain whether this intimate union between 
sense cells and axis cylinders is primary or secondary, they examined 
the conditions in two human embryos. One of these was obtained at 
the beginning and the other at the close of the second month of preg- 
nancy. It was found that many of the primitive cells of the forming 
ganglion of Scarpa show processes, some of which are directed toward 
the periphery and some toward the brain. In consequence the investi- 
Sot wei Se. Ape 
