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 in the 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 



