NEAL. — Nervous Syst. Squalus. 
PLATE 8. 
Stages in the development of the nerves oculomotorius, ramus ophthalmicus 
superficialis trigemini, and ramus ophthalmicus profundus trigemini. 
Fig. 58. 
Fig. 59. 
Fig. 60. 
Fig. 61. 
A frontal section of an embryo with 55 somites (8}-9 mm.). Embryo 
killed with Davidoff’s fluid. The oculomotorius appears as a cellular 
strand extending from the inner side of the mesocephalic (profundus) 
ganglion to the wall of the midbrain. Magnified 500 diameters. 
Reconstructed from three sections. 
A sagittal section of an embryo with 56 somites. Embryo killed with ` 
Davidoff’s fluid. Near the brain the nerve appears composed of loose 
fibrille, while peripherally it is cellular in appearance. Magnified 360 
diameters. Reconstructed from five sections. 
A combination of two parasagittal sections through the left side of an 
embryo of 16 mm. Protoplasmic processes from the ramus ophth. sup. 
trig. appear in relation with the anterior projection of the 2d cavity 
(muse. obl. superior). Magnified 70 diameters. 
A parasagittal section from the right side of an embryo with 51 or 52 
somites (8 mm.). A well marked fibril passes from the mesocephalic 
ganglion to van Wijhe’s Ist somite. The oqulomotorius has not yet 
appeared. 
