Dixon—On the Development of the Branches of the Fifth Cranial Nerve in Man, 49 
origin. Still the idea that the ciliary ganglion is in some sense the homologue 
of a spinal ganglion has supporters. Dohrn believes its origin to be different 
from the origin of true sympathetic ganglia. Speaking of the ciliary ganglion, 
he says, ‘“‘letztere diirfen also keinesfalls mit den bisher ausschliesslich sympa- 
thische Ganglien genannten Bildungen in eine Kategorie geworfen werden.”* 
Von Gustaf Retziust has, however, since shown that in the foetus of the cat the 
ciliary ganglion contains ‘‘nur multipolar Nervenzellen von echte sympathischen 
Typus.” These last observations of Retzius were made by Golgi’s method of 
staining, and must be looked upon as conclusive in their results. 
This conclusion, that the cells of the ciliary ganglion are of sympathetic type, 
agrees with the important observations of Langley and Anderson,{ who, from a 
Te: 
Ree SS 2 
Fiaure 3. 
Camera lucida drawing of a portion of section corresponding to the dotted outline in figure 2. The actual section from 
which the drawing was made lies 50 « lower in the head than the one shown in figure 2. The lettering is the same as in 
figure 2, except that Ist. should read Isth. 
study of the effects of nicotine on the ciliary ganglion, came to the conclusion 
‘that limiting attention to what has been actually proved about the ciliary 
ganglion there can be no hesitation in considering it as homologous with a sympa- 
thetic ganglion, although its nerve cells have no connection with the cervical 
sympathetic.” Gaskell,§ who earlier still believed the ciliary to be a sympathetic 
* Mittheilungen aus der Zool. Station zu Neapel, 1891, Bd. x., p. 32. 
+ Anatomischer Anzeiger, 1894, p. 633. 
t “On the Action of Nicotine on the Cells of the Ciliary Ganglion, and on the Endings of the Third 
Nerve,” Journal of Physiology, vol. xiii., 1892, p. 460. 
§ ‘‘On the Relation between Structure, Function, Distribution, and Origin of the Cranial Nerves ; 
together with a Theory of the Origin of the Nervous System of Vertebrata,” Journal of Physiology, 
vol. x., 1889, p. 153. 
