THE  CANADIAN   JOURNAL.

                   NEW SERIES.

           No.  XCV.— JULY,  1877.
 

LEFTHANDEDNESS.
 

BY DANIEL WILSON, LL.D., P.E.S.E.
 

  Under the title of " Bighthandedness," the specialities of this

common attribute of man, and the sources and characteristics of the

occasional deviation from it, have been discussed in a former paper,*

I now propose, under the present title, to supplement it with some

additional suggestions and illustrations.

  If righthandedness can  be  referred to any  anatomical cause—

such as the position of the viscera, their relative weight on the two

sides of the body, the development of the subclavian arteries, or the

predominance of one of the  cerebral hemispheres,-—then its general

prevalence, or assumed universality, among all races and in all ages,

is easily accounted for;  and  lefthandedness  may be traced, with

reasonable probability, to a reversal of the normal anatomical con¬

ditions of the body.   But  no theory is of any value which  fails

to account for the exceptional lefthandedness, no less than for  the

prevalent righthandedness.  The evidence of  righthandedness  as a

predominant habit is obvious; but  its source is not yet  certainly

determined, and acquires a  fresh interest in. so far as this natural

endowment  or habit is peculiar to man.

  If righthandedness is referable to> anatomical causes, some traces

of it may be looked for among mammalia generally, and especially
 

* Canadian Journal, N, S., Vol. xiii., p. 193.