ar 
A comparatively early stage, perhaps not the earliest, of this con- 
dition may be seen in fig. 5. The embryo (R. batis) measured over 
22 mm. and the full number of somites and gill clefts was present. 
Fig. 5. Transverse section of 
a R. batis of 22 mm. 
The „Randschleier“ (Hıs) of the cord was well marked, and 
muscle substance was as yet only developed in the more central 
portion of the myotome; that is,”its dorsal apex was quite cellular. 
As shown in the figure, the spinal ganglia (sp. gl.) of this region had 
become connected with the cord. 
The figure illustrates more particularly the following: 
a) A number of macro-ganglion cells (gl. c’), lying in the dorsal 
portion of the spinal cord, 
b) from one of these a fine axis cylinder proceeding through the 
formative tissue of the mesoderm (not drawn in), and ending in 
c) a ganglion cell (gl. c’.) which lies within the myotome (mp.). 
It will presently be recognised that this figure neither represents 
an abnormality, nor is drawn from the imagination. I possess very 
many such preparations, some of which vary in some slight detail 
from the one here given — a pretty example will be referred to 
presently. 
I have long been aware of the existence of such ganglion cells 
within the myotome, especially in later stages, but a knowledge of 
the fact did not in the least afford a key to the mystery of their 
meaning and purpose. 
An insight into these was only to be obtained by observation 
and what that word signifies in this particular case few perhaps imagine. 
With the eight illustrations given the facts about this larval nervous 
system, its nature and functions, appear to be so plain and simp e 
that the reader is perhaps more inclined to marvel that the facts 
