195 
Whenever one of these macro-nerves is met with on the one side, 
there is almost invariably a similar, not: always identical, one on the 
opposite side of the body. 
It was stated that the macro-ganglion cells or their (naked) axis 
cylinders appear to strive towards the tips of the myotomes: this is 
the rule, as will presently be evident. 
In some embryos, but not by any means in all, another interesting 
and hitherto unheard of phenomenon in Vertebrate embryology is 
noticeable. An embryo with 83 somites (3 less than that of fig. 1) 
illustrates this in a remarkable fashion. 
A combination drawing of several sections is reproduced in fig. 2. 
Two nerves (s. e. n.) 
with applied nerve-form 
ing nuclei, are seen pro- 
ceeding from almost the 
dorsal margin of the cord, 
one on each side, arching 
over the myotomes, and 
running downwards to- 
wards the haemal aspect 
of the body, in their 
course lying just under 
the epiblast and to the 
outer side of the myo- 
tome. A mode of termi- 
nation } otherwise than 2 Fig. 2. Transverse section of the trunk of a R. 
7 batis of 9 mm. 
as shown in the figure, 
has not yet been deter- 
mined either in this or in any other case. If these subepiblastic nerves 
are met with in any embryo, they occur in numbers, and in this parti- 
cular series of sections very many such nerves are present. From 
what will shortly be described, I am quite prepared for the discovery 
that ganglion cells or, (what is much the same thing) nerve-forming 
cells may be found to be given off from the epiblast in loco along the 
path of these sub-epiblastic nerves, but as yet a direct observation 
cannot be recorded. 
Regarding the question as to the application (contact theory) of 
nerve fibres and ganglion cells, as opposed to fusion, about which 
much has of late been written !) it is of interest to find — and an 
1) Vide inter alia Rerzıus, Zur Kenutnis des Nervensystems der 
Crustaceen, Leipzig 1890. 
