THE SYMPATHETIC NERVOUS SYSTEM. 221 



ously identifies the latter with the intra- cranial r. recurrens 

 of the carp. 



Cole ('98a, p. 145) has shown that in many fishes the r. 

 pharyngeu IX may run forward accompanying this sym- 

 pathetic nerve to join the r, palatinus VII, thus consti- 

 tuting a true Jacobson's anastomosis like that of the 

 mammals. In Menidia the absense of the r. pre-trema- 

 ticus IX is correlated with the reduction of the r. pharyn- 

 geus IX. The sympathetic ganglion s^. /j. has, however, 

 a slight fibrous connection with the IX ganglion and 

 among these fibres there may be a few of the proper 

 glossopharyngeal fibres which run forward with the sym- 

 pathetic as a Jacobson's anastomosis. If such fibres occur, 

 they cannot be distinguished from the sympathetic fibres 

 and in any case their number would be very small. The 

 true nature of this anastomosis, where it occurs, was 

 recognized by Stannius ('49, p. 58, foot-note i), though 

 he did not make the homology with the Jacobson's anas- 

 tomosis. 



Continuing cephalad from the first sympathetic gan- 

 glion on the ventral edge of the Gasserian ganglion are 

 two sympathetic nerves, one the radix longa of the ciliary 

 ganglion, the other farther dorsad, the ramus ciliaris 

 longus, which pursues an independent course to the eye- 

 ball. The sympathetic ganglion from which they spring 

 {sy. i) is very intimately related to the Gasserian and in 

 places can be distinguished from it only by the small size 

 of its cells, though farther caudad the two ganglia are 

 quite distinct (Fig. 23). It then becomes bi-lobed (Fig. 

 24), the median lobe having only the characteristic small 

 sympathetic cells and giving off a branch {sy. rec. j) 

 dorsad through the substance of the Gasserian ganglion 

 for the third root of the r. lateralis accessorius, and farther 



