N0S.IAND2.] ANATOMY OF SCOMBER SCOMBER. 243 



scribed by Ewart in Lccmargus as branch i ; and that it is, accord- 

 ingly, not the homologue of the ophthahniciis superficiaUs trig- 

 emini of fishes. Dixon, on the contrary, incUnes to consider this 

 last nerve as the homologue of the frontal of mammals (No. 23, 

 p. 42 ) . As to the ophthalmic or mesocephalic ganglion of certain 

 descriptions of mammals he thinks it is simply "the cells of the 

 'nervenfiihrendes Gewebe,' which appears before the axis-cylin- 

 ders of the nerves are present, and from which the nuclei of the 

 white substance of Schwann are said to be developed." He here 

 makes special reference to His's work on human embryos, and to 

 Chiarugi's preliminary notice of his work on the guinea-pig. 

 Chiarugi himself, in his later publication (No. 13, p. 70), reasserts 

 the existence of a ganglion on the ophthalmic nerve of embryos 

 of the guinea-pig, and he considers it the homologue of Beard's 

 mesocephalic ganglion, that is, of the ganglion described by me 

 in Amia as the profundus ganglion. In the Torpedo, Chiarugi 

 says this ganglion is found on the ramus ophthalmicus superficiaUs, 

 an evident error either of observation or nomenclature. The gang- 

 lion described by His on the ophthalmic nerve of human embryos, 

 Chiarugi considers as an early stage in the development of the 

 ciliary ganglion, and of this latter ganglion, in general, he says 

 (loc. cit., p. 70), "Tutte queste particolarita sono un probabile 

 indizio che dalla branca oftalmica derivi il ganglio ciliare ; I'ab- 

 bozzo del ganglio si distaccherebbe prococemente da essa e por- 

 tandosi ventralmente si svilupperebbe in contatto e in rapporto 

 col lir pajo." 



Holtzmann (No. 41) finds that the ciliary ganglion, in birds, is 

 not connected with the trigeminus by a branch that arises directly 

 from it, but by a branch that always arises from the ciliary nerves 

 distal to their origin from the ciliary ganglion. Between this con- 

 necting branch and the ganglion there is, however, an important 

 interchange of fibers, but whether these fibers run, from the con- 

 necting branch, proximally along the ciliary nerve into the gang- 

 lion, or vice versa from the ganglion into the connecting branch 

 he is not sure. Of the cells that form the ganglion he says : "Ich 

 habe daher keinen Grund, an der rein spinalen Natur der Zellen 

 des Ciliarknotens der Vogel zu zweifeln." In the cat, on the con- 

 trary, he finds them all of a purely sympathetic character, as does 



