470 
ihe J’asciculus communis component of the VII might represent the 
Portio intermedia of higher forms. If this be true, its ganglion would 
correspond, in part at least, to the geniculate ganglion and the small 
branch to the lower jaw would represent the Chorda tympani. ‘There 
cau be uo question, 1 think, but that in origin, course and distribution 
this branch most closely approaches the Chorda. 
2. Frormep (“Über das Homologon der Chorda tympani bei nie- 
deren Wirbelthieren”, Anat. Anz., Jahrg. I, No. 15, Juli 1887) has 
expressed the view that the Chorda tympani is represented, in Se- 
lachians, by a branch to the lateral sense organs of the lower jaw 
similar to the Rr, buccalis and ophthalmicus superticialis facialis to 
the lateral sense organs of the upper. There exists such a brauch in 
Awphibia but it belongs to the “dorsal VII” and is entirely different 
wm origin, in the character of its fibres and in their distribution from 
the branch here homologised with the Chorda and, between the two, 
the latter undoubtedly most closely resembles the Chorda. A further 
difficulty in the way of homologising any of these lateral nerves with 
nerves in the higher vertebrates lies in the fact that the former dis- 
appear in terrestrial Amphibia. FrorıEp’s error probably does not 
arise from describing the wrong branch but in characterising that 
brauch as one of those supplying lateral sense organs. ‘The cause of 
this will be shown in a subsequent paper. 
3. The importance of ascertaining and bearing in mind the com- 
posite character of the cranial nerves is further shown in BEARD’S 
suggestion that the taste buds of the mouth are derived from lateral 
sense orgaus which wandered in from the surface. ‘his he supports 
by the fact of the innervation of the latter by the IX. On analysis, 
however, this supposed support is seen to be illusory inasmuch as the bran- 
ches of the 1X innervating lateral sense organs are derwed from a com- 
ponent of the IX corresponding to the “dorsal VIL”, while the bran- 
ches of the IX supplying parts of the mouth arise from an entirely 
different component, one probably derived from the Fasciculus com- 
munis. ‘thus their innervation is in reality distinctly difierent and 
negatives BEARD’S suggestion rather than supports it. The lateral 
sense organs deem a distinct and differentiated system and being so 
developed canndt be used as a starting point in the phylogeny of all 
other sense organs. Judging from innervation, the auditory organ 18 
the only one whose connection with this system seems probable. 
4, Rast (“Uber das Gebiet des Nervus facialis”, Anat. Auz., 
Jahrg. Il, No. 8, Apr. 1, 1887) explains the change of the VII from a 
