312 G. E. COGHILL 



Figs. 7, 8, 9 Non-motile stage (No. 467). X 50. 



Fig. 7 (section 1-3-12) illustrates the adhesion of the ophthalmic ganglion 

 to the skin (Ad.G.oph.) dorsally of the eye, and the relation of the eye to the 

 olfactory epithelium (0//.). 



Fig. 8 (section 1-4-3) is 120 fx caudad of figure 7 and shows the constricted 

 nature of the root of the ophthalmic ganglion, although at this level it is still 

 ganglionic, also the relations of the retina, optic stalk and brain. 



Fig. 9 (section 1-4-8) shows the adhesion of the Gasserian ganglion {G.G.) 

 to the skin at Ad., just ventrally of the lateral line primordium iSup.L.L.). 

 These drawings are made from the same embryo as is figure 1, with which they 

 should be studied. 



Fig. 10 Non-motile stage (No. 546, section 4-3-1). X 50. The section- lies 

 approximately in the frontal plane, and shows favorably the two divisions of the 

 ophthalmic ganglion {G.oph.) and the adhesion of one of these divisions with the 

 skin (Ad.). Farther caudad the Gasserian ganglion appears in section (G.G.). 

 A little farther caudad is the ectodermal thickening that is associated with the 

 spiracular pouch (Ec. Th.). 



Figs. 11 and 12 Non-motile stage (No. 455, sections 2-1-10 and 13). X 50.' 

 The plane of section is longitudinal and latero-ventral, favorable to show the 

 relations of the ophthalmic and Gasserian ganglia and their roots. 



Fig. 11 shows the two divisions of the ophthalmic ganglion, a and h. Fig. 12 

 is 30 M farther ventrad and shows the root connections of these nerves with the" 

 brain [R.V). Around the base of these roots is amass of cells iR.M.) which does 

 not seem to be a part of the ganglia at this stage. I have called this the root 

 mass. The preauditory lateral line ganglion and the visceral sensory ganglion 

 of the facial nerve (G.VII) are represented as a single mass. Its rostral end is 

 in contact with the entoderm of the spiracular pouch. 



Fig. 13, 14 and 15 Early flexure stage (No 473, sections 1-3-14, 1-4-6 and 1-4-12 

 respectively.) X 50. These sections are selected from the series from which 

 figure 2 was made, and should be compared with it. 



Fig. 13 illustrates the ophthalmic ganglion after it has detached itself from the 

 ectoderm, leaving an ectodermal thickening at Ec.Th. 



Fig. 14 shows the attenuation of the root of the ophthalmic ganglion (R.oph.) 

 160 fi caudad of the last figure and at the level of the caudal portion of the eye. 



