Caopenteb. — Oculomotor Nerve iu Chick. 



PLATE 4. 



Fig. 11. Section transverse to longitudinal axis of mid-brain of an embryo in 

 Stage III (88 hrs. incubation), showing root of oculomotor nerve. 

 Fixed in corrosive-acetic mixture and stained with iron lisematoxylin. 

 X 600. 



Fio. 12. Keconstruction from seven consecutive parasagittal sections througli an 

 embryo in Stage III (93 hrs. incubation), viewed from left side, and 

 showing longitudinal section through distal portion of ophthalmic 

 branch of trigeminal nerve. Fixed and stained in vom Rath's fluid. 

 X 66. 



Fig. 13. Diagram of relations between fundament of ciliary ganglion and oph- 

 thalmic branch of trigeminal nerve. Beconstructed from 28 consecu- 

 tive sections transverse to longitudinal axis of mid-brain of an embryo 

 in Stage IV (100 hrs. incubation). In the Figure dorsal is up, median 

 to the left. Ganglion cells a, fl, 7, S, f, correspond to ganglion cells 

 with the same designations in Figure 16 (PI. 5). X 200. 



Fig. 14. From an embryo pig. A, Proximal end of neuraxon of oculomotor 

 nerve. B, Longitudinal section through oculomotor nerve midway in 

 its course. Fixed in corrosive-acetic mixture and stained with Brazilin. 

 X 733. 



