Drxon—On the Development of the Branches of the Fifth Cranial Nerve in Man. 39 
According to this last author, in amphibia, a ‘“ partial division of the anterior 
extremity of the Gasserian ganglion is the only sign of separation between the 
ganglion of the Rr ophthalmicus and maxillo-mandibularis trigimini respectively.” 
When now we attempt to compare what is found in these lower animals, with 
what is known for man, we find that Professor His describes the condition of the 
Gasserian ganglion in an embryo in which only the rudiments (Anlagen) of the 
ganglia are present, the nerve roots not yet having appeared, as follows* :— 
‘Die obere Ecke des Ganglions verliingert sich in einen Strang welcher an die 
Augenblase herantritt, das vorderste Ende desselben kommt als Anlage des G. 
ciliare tiber den Stiel der Augenblase zu liegen”; and again, writing of the Gasserian 
ganglion, he sayst :—‘‘ Von seinem vorderen Ende erstreckt sich em verjiingter 
Fortsatz bis hinter die Augenblase, als Anlage des G. ciliare.” Beard,{ referring 
to this description and the figure given by Professor His, says:—‘‘From the above 
account and the examination of the figures given by Professor His, I do not enter- 
tain the slightest doubt that what he thus describes is really the rudiment (Anlage) 
of the mesocephalic ganglion.” 
Professor His,§ writing more recently still, considers that the ganglion described 
by him is the same as that seen by Marshall, Schwalbe, and others, and that it 
represents the ciliary ganglion. He states that Beard is wrong in calling it 
mesocephalic, and that in man, at least, the fibres of the ophthalmic division of 
the fifth nerve are not derived from its cells. ‘‘ Das Ganglion ciliare als solches 
entwickelt sich aus dem Gesammt-complex der Trigeminusganglien als dessen 
vorderster, der Augenblase anliegender Theil. Man kénnte dasselbe kurzweg als 
das Stammganglion des R. ophthalmicus bezeichnen, falls sich erweisen liesse, 
dass die Fasern des letzteren ganz oder doch zum grésseren Theil aus seinen 
Zellen entstehen. Dies ist indessen beim Menschen sicherlich nicht der Fall, bei 
welchem die lange Wurzel des Ganglions den Maximalbetrag von Fasern ergiebt, 
denen das G. ciliare als Ursprungsort zugetheilt werden kann.” 
Beard’s ganglion being the homologue of a ganglion on a posterior nerve root 
cannot then be represented by this forward prolongation of the Gasserian ganglion 
inman. From my observations on Professor His’s specimens, I believe that the 
ganglion of the nasal, or ramus profundus, if it exists at all in man, is so completely 
fused with the Gasserian ganglion, that the nasal and frontal nerves appear simply 
as branches of the latter. Further, it appears to me that the forward projection 
* « Anatomie Menschlicher Embryonen.” Part I., p. 106. See also fig. Al, plate vz. of Atlas. 
¢ Page 44. . 
t “The Ciliary or Motor Oculi Ganglion, and the Ganglion of the Ophthalmicus Profundus in Sharks.’ 
Anatomischer Anzeiger, 1887, p. 567. 
§ ‘‘ Die Morphologische Betrachtung der Kopfnerven.” Archiv fiir Anatomie und Physiologie. Anat. 
Abtheilung, 1887. Heft vi., p. 421. 
