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infinite anastomoses form minute meshes; these nervous fibrillæ 
spring from cell-processes, as well as from nerve-fibres. If Hallers 
illustrations of the central »Nervennetz«, are compared with Leydigs 
of the dotted substance, the resemblance must certainly strike ever}- 
body. The only difterence is that, Leydig calls his reticulation a 
spongioplasmic one, in the cavities of which the real nervous sub- 
stance is diffused, whilst Haller calls his reticulation a nervous one, 
the fibrillæ of which are surrounded by interfibrillar substance. It 
may indeed be the same so far, because in both cases there must 
be a quite diffusive distribution of the nervous substance or nervous 
reticulation in the central nervous system. The cell-processes which 
contribute to the formation of this reticulation are, according to Haller, 
those which do not directly unite with other cells, and which do not 
directly form peripheric nerve-tubes; the latter he calls »Stammfort- 
såtze«. He even illustrates isolated cells with processes forming a 
reticulation. 
The nerve-tubes have Uvo modes of origln, some tubes originate 
directly in ganglion cells, and are direct continuations of »Stamm- 
fortsatze«, other tubes originate in the central »Nervennetz«. 
No previous writer has so decidedly and emphatically maintained 
an infinitely anastomosing, reticular, character in the central dotted 
substance. 
At about the same time as Béla Haller, the writer of this 
paper published a Memoir on the structure of the Mysostoma and, 
subsequently, a paper on the nervous system of the Ascidia and 
Myxine. We have there maintained views very similar to those 
which will be laid forth here, and will therefore now refer to them 
somewhat cursorily only. The dotted substance is no anastomotic 
nervous net-work, but a complicated web or plaiting of nervous 
fibrillæ or tubes. In transverse sections a reticulation is certainly 
seen, it is, however, to a great extent produced, by the transsection 
of the sheaths of tube-shaped fibres traversing, or rather forming, the 
dotted substance; the reticulation is thus a rather apparent one and 
is of a „ spongioplasmic" nature. It is, consequently, the same 
substance which Leydig has described under this name, but it has 
not, in the writers opinion, the reticular structure he has ascribed to it. 
Each cell has only one, really ^nervous process", if the cell 
has several processes, then the other ones are protoplasmic pro- 
cesses with a nutritive function. The » nervous processes « pass 
to the » dotted substance «, and, there, they — either quite lose 
their individuality and sub-divide into fibrillæ, losing themselves in 
