374 On the Morphology of the Semicircular Canals. (June, 
machine, the various functions of which we wished to determine. 
Now, what would we think of a man who would plunge a knife 
through crystal, dial, mainspring and all, to find out how the 
thing worked. Is the proceeding in the case of an animal any 
less absurd? Is it more encouraging to know that the machine 
with which we are dealing is infinitely more complex, and of the 
fundamental truths of whose construction we can only gain vague 
and fragmentary ideas ? 
In order to understand a complex organ—if, indeed, the attain- 
ment of such an end be possible—I believe that we must cast 
about for the most widely scattered facts, and then view these in 
the broadest possible light. I believe, therefore, that the only 
way to understand an organ for the perception of sound vibra- 
tions, is also to study organs for the perception of allied vibra- 
tions, and then to compare the various principles involved in the 
development, structure and function of each. By the pursuance 
of such a method in the present instance, the conclusions which 
seem to be pointed out, are, first, that the chief significance of the 
semicircular canals is morphological, and secondly, that their 
functional importance, though considerable, is secondary. If, in 
the above discussion, I have merely raised this view of their 
nature to the degree of a probability—which is the most that cir- 
cumstances allow—my object is accomplished. 
Addendum.—After the reading of the above paper, Dr. A. J. 
Parker offered a suggestion with regard to the function of the 
semicircular canals which makes the parallelism between these 
structures even more apparent. His view, which he permitted 
me to append, is as follows: 7 
He says that the maculz acusticz are very probably situated in 
just those parts of the labyrinth on which the sound- waves 
impinge with the greatest intensity. This being the case with the 
macule of the ampulla, the sound-waves probably enter the 
ampullar ends of the canals with much greater force than they 
enter the non-specialized ends. Consequently, when interference 
takes place, it occurs in or near these non-specialized ends, f. e., 
where there are xo acoustic spots! Dr. Parker looks upon the 
semicircular canals as so many conduits to carry off vibrations after 
they have impinged on the maculz of the ampulla. This would 
make their function exactly analogous to that of the lateral canals. 
Dr. Parker’s view also explains why each semicircular canal 
has but ove ampulla, and why-this should be situated at the ed, 
pa instead of other parts of the tube. 
