46 The Ohio Journal of Science [Vol. XVII, No. 2, 



Plate III. 



Figure 10 is a detailed drawing of the profundus at the level of Figure 9. The 

 definite boundaries and compactness of the ganglion stand out clearly in the figure. 

 This figure also illustrates the relation of the ganglion to a supra-orbital placode 

 (PI), the nuclei of which show a radical arrangement. Sec. 68 X175. 



Figure 11 is a detailed drawing of the profundus at the level of its root in the 

 medulla. The root is cellular, as the figure shows and is at this level separate 

 from the root of the Gasserian. Sec. 86. X175. 



Figure 12 is an outline of the section of which a portion is detailed in Fig. 11. 

 Sec. 86. X 27. 



Figure 13 is a detailed drawing of the trigeminal complex seven sections 

 posterior to the beginning of the root of the profundus. This figure is drawn from 

 the left side of the section because it showed the double root more clearly than 

 the right side. Sec. 93. X 175. 



Figure 14 is an outline of the section of which a portion is detailed in Fig. 13. 

 Sec. 93. X 27. 



Figure 15 is a detailed drawing of a portion of the Gasserian ganglion at the 

 level of Fig. 16. Only the part over the gill pouch is detailed. The close relation 

 of the ganglion to a lat. line placode (pi.) is shown and also its contact with the 

 endoderm (en) of the gill pouch. vSec. 94. X 175. 



Figure 16 is an outline of the section of which a portion is detailed in Fig. 15. 

 Sec. 94. X27. 



Figures 17 to 27, inclusive, are from the same embryo (Plcthcdon gl. Stage B, 

 ■6 mm.) from which the first reconstruction Fig. 32 was made. 



Figure 17 is a detailed drawing of the profundus ganglion with the ectoderm 

 v(ec) is shown and also the irregular outlines of the ganglion. Sec. 45. X 175. 



