MULTIPLE NEUROMATA OF THE CENTRAL NERVOUS SYSTEM. 739 
Nore on GENEsIS OF Fipres IN TuMouRS OF THE CENTRAL Nervous SYSTEM. 
(a) Ghoma and Neuro-glioma. 
Verocay (1910).—In the previous section we have seen that VeRocay regards the 
early embryonal neurocytes as capable of differentiating to form ganglion cells, glia 
cells, and nerve fibre cells. From this it will be readily understood that the combina- 
tion of glioma with multiple tumours of nerves found in both of his cases is looked 
upon, not as an accidental occurrence, but is traced to the same developmental 
disturbance. He believes that when multiple tumours of nerves are more minutely 
investigated this combination will be found more frequently. 
ScHMINCKE (1910) has described a case of ganglio-neuroma of the brain in a man 
seventeen years old. The tumour was the size of a large nut, was situated in the 
anterior portion of the temporal lobe, and was not defined from the surrounding tissue. 
Microscopically, the tumour consisted of the.several components of the nerve tissue, 
all in varying degrees of differentiation: (1) ganglion cells in different stages of 
development, distinctly recognisable as ganglion cells by their characteristic nucleus and 
general morphological structure; (2) numerous glia cells of various form and size and glia 
fibrils ; (3) syncytial neuroblast chains consisting of fibres with inserted nuclei, showing 
a definite axis-cylinder but no myelin sheath, and therefore representing nerve fibres 
in different stages of development. ScHMINCKE considers that the presence of these 
syncytial neuroblast layers may shed some light upon the development of fibres within 
the central nervous system. ScHMINCKE holds that proof has been given in favour of 
the formation of the peripheral nerve fibres from. neuroblast chains, but as yet no proof 
of a similar origin of the fibres within the central nervous system. For an explanation 
of this tumour ScHMINCKE goes back to the detachment of a portion of embryonic 
nerve tissue and believes that the embryonic neurocytes have differentiated along the 
three lines to form ganglion cells, glia cells, and nerve fibre cells. He suggests that 
the powers slumbering in this tissue have become active and have succeeded in 
completing their differentiation. Neuro-glomata have thus the same origin as 
gliomata ; there being no proliferation on the part of pre-existing ganglion cells, but 
all the cells of the tumour representing earlier or later stages of development of 
original indifferent embryonic cells in which the process started. These cells are 
often far from any normal type. 
(b) Neuroma of the Central Nervous System. 
The literature referring to neuroma of the central nervous system is very scanty 
and scattered. arly findings of tumours consisting of nerve cells and medullated 
nerve fibres refer chiefly to small nodules on the surface of the ventricles in hydro- 
cephalus. As the microscopic technique was at the time very deficient, their value 
