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the #Glaskörper” with a striated wall, as it is found in the eye- 
cells of the Hirudines. As is the case with those eye-cells, here in 
Amphioxus too the vitreous body seems to be filled with a granular- 
looking substance (coagulation?) but this was not always clearly to 
be seen. 
Between this body («), that lies close to the pigmented cap, and 
the nucleus (fig. 14) lying at the other side of the eye-cell, there 
is in most cases to be seen another beanshaped body, that does not 
possess a striated wall, but by a clearer tinction with protoplasmic 
dyes and a more homogeneous substance may be distinguished from 
the darker and more granular-looking protoplasm of the cell (fig. 14). 
This body seems to be connected with the perception of light by 
the eye-cell in the same way as the vitreous body described above. 
The arrangement of the neurofibrillae in the eye-cells seems to point 
to this conclusion. Entering the cell at the ventral side of the 
nucleus, there, where according to Hesse the eye-cell is drawn out 
to a point, the neurofibril forms a loosely built network round the 
nucleus. From this network large neurofibrils ascend through the 
cell and take the beanshaped body (4) between them (fig. 2, fig. 3). 
Between this body and the pigment-cap these neurofibrils anastomose 
again and form a second net, which seems to enclose the vitreous body 
(a) with the striated wall. How the further course of these fibrils is 
between the vitreous body («) and the pigment-cap I could not deter- 
mine with any accuracy. 
To obtain good results with the chlorid of gold-method of ApitHy 
the sections may not be very much thinner than 10 a. Now for 
the study of the eve-cells it is necessary to make sections of about 
6 to 7 u, because in thicker sections the black pigment of the 
capshaped cell embraces the greater part of the eye-cell and shuts 
it out from view. It is therefore not possible to get those deep 
black neurofibrillae, which may be seen so distinctly in the prepara- 
tions of Aparny (the more so as the neurofibrillae of Amphioxus 
are thinner than those of Hirudines); and even in sections of 
6 to 7 u that part of the neurofibrillae-network, which is lying 
beneath the pigment-cap is entirely concealed by the pigment-grains. 
Probably the network is continuous and anastomoses at the other 
side with the more ventrally lying network. 
In what manner the neurofibrillae leave the eye-cell I could see 
only in a few cases. The fibril seemed then to proceed horizontally 
for some tinre but could not be followed any farther. 
B. The neurofibrillae in the ganglion-cells. 
On the neurofibrillae in the ganglioncells Ill say only a few words, 
