248 ALBERT KUNTZ 



According to Beraneck ('84), the ciliary ganglion arises in 

 intimate association with the oculomotor nerve and later becomes 

 connected with the ophthalmic division of the trigeminal nerve. 

 He expresses no opinion, however, as to the source of the cells 

 taking part in its development. 



According to Hoffmann ('85), the anterior part of the neural 

 crest gives rise to two ganglia, viz., the mesocephalic ganglion 

 associated primarily with the ophthalmic division of the trigem- 

 inal nerve, and the Gasserian ganglion. A large mass of cells, 

 according to this author, becomes separated from the peripheral 

 end of the mesocephalic ganglion and advances along the path 

 of the fibrous ramus extending from the latter toward the oculomo- 

 tor nerve to a point in proximity with the latter nerve. This ag- 

 gregate of cells gives rise to the ciliary ganglion. 



According to the writer's observations on embryos of the log- 

 gerhead turtle (Thalassochelys caretta), the anlage of the ciliary 

 ganglion arises as an aggregate of cells in the path of the oculo- 

 motor nerve. This nerve arises from the ventral aspect of the 

 mesencephalon by a fan-shaped root arranged longitudinally 

 (fig. 1 1 , oc) . Its fibers are accompanied by numerous cells obvious- 

 ly of nervous origin. Such cells are closely aggregated in the 

 root of the nerve outside the external limiting membrane, while 

 within the wall of the mesencephalon cells push out from the 

 mantle layer in cone-shaped masses into the nerve-root as it 

 traverses the marginal veil. The cells advancing peripherally 

 along the oculomotor nerve, therefore, are obviously cells which 

 have wandered out from the wall of the mesencephalon, or the di- 

 rect descendants of such cells. As these cells advance peripherally 

 many of them become aggregated in the path of the oculomotor 

 nerve and give rise to the ciliary ganglion. 



In embryos of eight days incubation, the anlage of the ciliary 

 ganglion appears as an elliptical aggregate of cells in the path of 

 the oculomotor nerve near its growing tip (fig. 11, cilg). No con- 

 nection can be found, at this stage, between the anlage of the cil- 

 iary ganglion and the ophthalmic division of the trigeminal nerve. 

 In embryos of nine days incubation, a slender fibrous ramus aris- 



