181 
one of them being innervated, contrary to my expectation, from the 
recurrent (otic) branch of the buccal, I made a very careful examination 
of it and found that the canal had avery distinct ampulla 
of the compound type, and exactly resembled those 
found in the superficial ophthalmic group. Neither was 
the canal like those figured by CoLLinGE. There is no inherent 
improbability in Mr. CoLuınar’s account, and it may very possibly 
turn out to be perfectly correct, but Leypia (17) only described one 
type of ampullary canal in Chimaera, and I am rather inclined, 
from my own cursory examination, and the little fact mentioned above, 
to await confirmation of Mr. CoLuınar’s results. His description of 
the innervation of the ampullary canals as only from the Vth is of 
course erroneous, and should be only from the VIIth. | 
My only other difference with Mr. CoLLInGE is as to the nomen- 
clature of the sensory canals. As Auuıs and Ewart have already 
pointed out, the only classification of the canals that has the least 
value or scientific foundation is that in which they are named accord- 
ing to their innervation and not according to the position they may 
happen to occupy in any particular animal. Their position is subject 
to extreme variation — their innervation, in all forms that have been 
properly investigated, is not. Hence the only method of determining 
the homology of any canal is to ascertain its innervation, and only 
when this has been done most carefully has the name of a canal any 
scientific value. Whether Mr. CoLLıngeE has done this, I cannot say, 
as he confines himself to general statements, and is apparently un- 
acquainted with the details of the innervation of the canals. It only 
remains for me to add that in my full paper the sensory canal system 
of Chimaera will be figured upon the plan adopted by Ewarr — 
i, e. every sense organ will be figured with its respective nerve twig. 
ALLIS’ otherwise beautiful drawing unfortunately only shows the peri- 
pheral distribution of the sensory canal nerves, and not their roots. 
Royal College of Science, South Kensington, 
April 30' 1896. 
Bibliography. 
1) Corz, F. J., Proc. Roy. Soc. Edin., Vol. XXI, 1896, p. 49. 
2) Cortiner, W. E., Proc. Zool. Soc., April 1896. 
3) MARSHALL and Spencer, Q. J. M. S., Vol. XXI, 1881. 
4) Wisne, van, Natuurk. Verh. Kon. Akad., DI. XXII, 1883. 
5) Brearp, J., Q. J. M. S,, Vol. XXVI 1886. 
6) Ewart, J. C., Proc, Roy, Soc., Vol. XLV, 1889, 
