EXPRESSION. 59 
lation of physical movements and mental actions ; 
they depend, probably, altogether on the mechanism 
of the nervous system. The nervous centres acted 
on by an excess of emotion’are deranged ; and it 
would require a far more intimate knowledge of 
cerebral function than has yet been arrived at to 
enable us to follow the details of the causation of 
the convulsions produced. Laughter, sobbing, and 
crying have the feature in common of convulsive 
breathing. In laughter, perhaps in symbolical con- 
nection with desire for the outflow of emotion, the 
expirations are accentuated and prolonged, and are 
therefore most obviously broken with convulsive 
quiverings ; in sobbing, on the contrary, the inspira- 
tions are elongated and. broken into a number of 
convulsive acts ; while in the crying of children the 
true sobbing is mixed with a desire to announce 
their sufferings loudly abroad, and, therefore, the 
convulsive inspirations are followed by an unneces- 
sarily long expiration, utilised, if I may use the 
expression, for the purpose of howling. But it is 
interesting to note that the extreme distortion of 
the face in the most violent crying is not dissimilar 
from that inthe most violent fit of laughter ; and an 
amusing illustration of this can be obtained by turn- 
ing up Plate I. fig. 2 of Mr. Darwin’s work on 
Expression, which represents a little child with eyes 
