234 



BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



et se devise en deiix parties (PI. XIY. Fig. 8) dont les fibres sortent du 

 cerveau en formant differents coins et se croisent ensuite au dedans du 

 ganglion Gasseri; de cette maniere le raraus ophthalmicus profundus les 

 recoit de la partie posterieure ; le ramus maxillaris, de la posterieure et 

 de I'anterieure ; le ramus mandibularis, priucipalement de la posterieure." 

 [Mitrophanow's results are seen to differ markedly from mine as to the 

 relationship of the fibres of the ramus mandibularis. My results, how- 

 ever, agree with those of His ('88^ p. 365, Tab. II, Fig. 3) for the human 



^f^VJI.ae, 



VJJ hoi. 



Figure K. 



embryo. The clear relationship of the motor fibres of the trigeminus 

 with encephalomere III and the visceral part of van Wijhe's second cavity 

 appears to me a matter of considerable morphological importance, and 

 seems to establish the metameric relations of these elements. 



Fig. K. Parasagittal section through the left side of a Squalus embryo of 

 19-20 mm. X 50. 



II, III, IV, second, third, and fourth encephaloraeres ; V. md., r. mandibularis 

 trig. ; V. mx., r. maxillaris trig. ; V. ojit. p'fnd., r. ophth. profundus trig. ; V. opt. su., 

 T. ophth. superficialis trig. ; V. rx. maj. and V. rx. min., major and minor roots of the 

 trigeminus; T7/. ac. , r. acustico-facialis ; VII. buc, r. buccalis facialis; VII. hoi., 

 r. hyoideus faciahs ; TT/. opt. su., r. opiith. superficialis facialis ; rjn. far., ganglion of 

 the facialis nerve ; fjn. ms-ce., meso-cephalic ganglion still retaining connection with 

 the ectoderm by the process x ; mu. ob. .sh., m. ohliquus superior ; )nu. rt. su. + a., 

 muse, recti superior and anterior (1st cavity) ; trch., trochlearis. 



