242 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
and regarding the neurofibrillae as the structures of primary import- 
ance, for then we should have two cell bodies corresponding to a single 
axis cylinder, and there would be no reason for regarding the neuro- 
fibrillae as dependent upon either cell body in any peculiar way. On 
the basis of such embryological evidence as has thus far been adduced, 
however, it appears that such relation as exists between the alleged 
neurofibrillae of the sense cells and those of the axis cylinders-is sec- 
ondarily established. The embryological investigations of London 
und Pesker (:06) to which I have already referred (pp. 218) have led 
them to view the alleged neurofibrillae of the sense cells as originating 
within the sense cells, and those of the axis cylinders as coming from 
the ganglion cells. ‘Uhey found no evidence for the existence of fibril- 
lae except in association with cell bodies,— either ganglion cells or 
sense cells, which latter they regarded as wholly like ganglion cells. 
Likewise Kolmer, as I have stated on page 219, affirms that the union 
between sense cell and axis cylinder appears to result from a growing 
together or interlacing of fibrillae some of which originate in the sense 
cell while others come from the axis cylinder. He believes that the 
union between the fibrillae of the sense cells and those of the axis 
cylinder is established secondarily, and is not the result of the growth 
of fibrillae from the axis cylinders into the sense cells or from the sense 
cells into the axis cylinders. He regards the sense cells as peripheral 
nerve cells. 
Finally, the embryological evidence obtained by Bielschowsky und 
Brihl bears out the conclusion that such union as exists between axis 
cylinders and sense cells is secondarily established. 
In view of this embryological evidence I am not able to understand 
why Kolmer, and London und Pesker consider it necessary to abandon 
the neurone theory, even if all the peripheral networks which have been 
described for this organ should meet with confirmation. ‘They them- 
selves regard the sense cells as peripheral nerve cells, which view is in 
complete accord with the interpretation given them by von Lenhossék, 
who has regarded them as short neurones. 
However, I am not yet prepared to accept these intracellular struc- 
tures as established. The testimony to their existence is scanty and 
inharmonious, the structure which Kolmer has described being totally 
different from those described by Bielschowsky und Briihl, who refuse 
to accept Kolmer’s results, characterizing them as an admittedly chance 
product, and suggesting that the appearance of the structure which 
Kolmer has interpreted as an intracellular network of neurofibrillae — 
may be due to over heating in the warm solution of silver nitrate 
which is used in the Ramén y Cajal process. 
