— 45 — 
his description of a connective tissue, or »VlRCHOW's Neuroglia ver- 
gleichbare Stutsubstanz« in the nervous system, he says, even, that he 
has not been able to distinguish the fibres of this » Stilt zsiib stan z^'' 
»von denjenigen der centralen, fibrillåren Punktsubstanz .... auch 
scheinen sie in dieselben iinmittelbar iiberzugehen. Ueber die ner- 
vose Natur der letzteren l^ann aber kein Zweifel obwalten.«') The 
mode of origin of these »nerve-fibres« Claparéde scarcely mentions, 
and it seems as if he agrees with Leydig, also, in regard to it. 
In his last memoir on the Annelids (1873) he gives a descrip- 
tion very similar to what is above quoted. 
SOLBRIG (1872) describes the »Punktsubstanz« as a granular 
fibrous mass which, in a successfuily isolated preparation, may be seen 
traversed by »einem merkwiirdig feinen Fasersystem, dessen Fibril- 
len an dem Rande des Praparates oft auf weite Strecken hin isoliert 
verfolgt verden konnen.« He compares this »Fasersystem« with 
the capillary reticulation of the vascular system, and supposes that a 
part of its function is to produce the correspondence of the unipolar 
ganglion cells with each other. Besides a direct origin of the 
nerve-tubes from ganglion cells, Solbrig also distinctly maintains an 
indirect origin from this »kornig-faserigen Masse «, the latter mode 
being the most common one. In this case the nerve-tubes are 
formed by the union of several »Fibrillen des feinen Fasersystems«. 
Stieda^) (1874) supposes the nerve-tubes of the Cephalopoda 
to be direct continuations of the processes of the ganglion cells. 
Such a relation, he has been able to observe in some few cases. 
»Ein anderweitiger Faserursprung lasst sich mit Sicherheit nicht de- 
monstriren.« He mentions some »feinsten Nervenfasern, kaum mess- 
bare Faden, welche ein im Centrum des Knoten belindliches schwer 
zur entwirrendes Netz bilden. « His view of the import or function 
of this »Netz« he does not, however, give.« 
The writer who has paid most attention to, and has made the 
most minute investigations upon, the central fibrous mass of the inverte- 
brate nervous system is, in my opinion, HERMANN (1875). This eminent 
investigator has, in his really classical memoir, given a very circum- 
stantial description of this substance, describing it as being granular- 
'fibrillous, and in which he very particularly indicates the course and 
origin of the fibres (1. c. p. 84 etc). 
1) 1. c. p. 595. 
^) I regret to say that to Trmchese's memoir on the nervous system of the 
Cephalopoda (1. c. 1868) I have had no access, as we do not posess it in the 
library of Bergen's Museum. 
