146 EDWARD PHKLPS ALLlS, JUN. 



of such a nei've as the so-called ramus profundus of Haller's 

 descriptions of Scyllium, in which fish the nerve is said 

 (p. 438) to be exclusively motor, and to be derived entirely 

 from the inner motor trigeminus root and the anterior upper 

 motor trigeminus nucleus. Tliat Haller has here certainly 

 mistaken a superficialis ophthalmic nerve for a profundus 

 one will be later shown. That he has also made some 

 further mistake is evident, for the superficial ophthalmic 

 nerve of Scyllium is certainly in no part a motor one. 



From the antero-dorsal corner of the intracranial gan- 

 glion of Mustelus a bundle of fibres, which Haller calls in 

 Scyllium the ventral "^ Wurzelportion " of the ramus ophthal- 

 micus superficialis, is sent forward and outward to join on its 

 ventral aspect what Haller calls the upper portion of the 

 posterior root of the trigeminus. This bundle of fibres, in 

 Mustelus, has its apparent origin from the intracranial 

 ganglion opposite the point where the inner motor trigeminus 

 root of Haller's nomenclature (my dorsal rootlet) joins it. 

 The fibres of the bundle, however, do not come fi'om that 

 rootlet, but come upward along the lateral surface of the 

 ganglion, from that part of the ganglion that has its origin 

 in relation to the dorsal portion of the fibres that arise from 

 the ascending fifth tract. The bundle is thus seen, from its 

 origin alone, to certainly be composed, in large part, of 

 general cutaneous fibres, and its peripheral distribution, to 

 be later given, shows that it is quite unquestionably entirely 

 so composed. Motor fibres certainly do not exist in it. 



From the posterior part of the intracranial ganglion 

 formed on this anterior trigeminal root the truncus maxillo- 

 mandibularis trigemini has its origin. Issuing from the 

 skull by the trigemino-facial foramen, this truncus, or root 

 of the truncus, there becomes more or less confused with the 

 root or stem of the facialis, and also with the hyoidean part 

 of the posterior trigeminal root. A large extracranial 

 ganglion is formed on these several stems. 



The so-called posterior root of the trigeminus, or Tri- 

 geminus II, is formed in Mustelus, as it is in Scyllium, of 



