206 EXPRESSION OF JOY: Chap. VIII. 



must be large; and it is perhaps to gain this end that 

 the corners are retracted and the upper lip raised. Al- 

 though we can hardly account for the shape of the mouth 

 during laughter, which leads to wrinkles being formed 

 beneath the eyes, nor for the peculiar reiterated sound 

 of laughter, nor for the quivering of the jaws, neverthe- 

 less we may infer that all these effects are due to some 

 common cause. For they are all characteristic and ex- 

 pressive of a pleased state of mind in various kinds of 

 monkeys. 



A graduated series can be followed from violent to 

 moderate laughter, to a broad smile, to a gentle smile, 

 and to the expression of mere cheerfulness. During 

 excessive laughter the whole body is often thrown back- 

 ward and shakes, or is almost convulsed; the respira- 

 tion is much disturbed; the head and face become gorged 

 with blood, with the veins distended; and the orbicular 

 muscles are spasmodically contracted in order to pro- 

 tect the eyes. Tears are freely shed. Hence, as for- 

 merly remarked, it is scarcely possible to point out any 

 difference between the tear-stained face of a person after 

 a paroxysm of excessive laughter and after a bitter cry- 

 ing-fit. 15 It is probably due to the close similarity of the 

 spasmodic movements caused by these widely different 

 emotions that hysteric patients alternately cry and laugh 

 with violence, and that young children sometimes pass 

 suddenly from the one to the other state. Mr. Swin- 

 hoe informs me that he has often seen the Chinese, when 

 suffering from deep grief, burst out into hysterical fits 

 of laughter. 



15 Sir J. Reynolds remarks (' Discourses,' xii. p. 100), 

 " It is curious to observe, and it is certainly true, that the 

 extremes of contrary passions are, with very little varia- 

 tion, expressed by the same action." He gives as an in- 

 stance the frantic joy of a Bacchante and the grief of a 

 Mary Magdalen, 



