399 
to the left of the centre of the body had been a sufficient 
determining cause in favour of the preferential use of the right 
arm by our species. 
Mr Nevitte GoopMan said that while he had listened with 
pleasure to the elucidation of Aristotle’s ideas on the causes of 
right-handedness he thought these indicated that the inductive 
method was preferable to the speculative. These ideas shewed 
how possible it was for an ingenious man with the great reper- 
tory of nature before him to adduce many facts to support any 
theory once formed. No doubt there were many facts which 
would support the idea that the right side had a preferential 
motor function. In addition to those named, the whole order of 
Gasteropods might be quoted, in which in the vast majority of 
instances the opening of the generative organs, the vent and_ 
the respiratory chamber, were on the right side. In fact an 
ordinary snail or whelk exhibited the phenomenon of an ex- 
cessive development of the right side, which excessive develop- 
ment had the effect of thrusting that side continuously over the 
other so as to result in the dextral helix. There were, however, 
many exceptions to this rule, as the Funis Contrarius of the 
Red Crag and numbers of existing shells, Clausiliz, &c. Flat- 
fish (Pleurovectide), the only animals of the vertebrate type 
markedly asymmetrical in their organs of relation, were by 
no means constant in having the right side of stronger motor 
function than the other; the upper, coloured, and more convex 
and muscular side being in many cases on the left. In the sole 
the developed side is usually the right, in the turbot usually the 
left. 
With regard to the prior motion of the right side from a 
state of rest he had narrowly observed horses’ paces and thought 
there was no ground for this supposition. The leading leg in 
the horse’s canter became so purely from training. Both dogs 
and young horses constantly change the leading leg when 
running unrestrained. All the figures in Egyptian Art had 
