Chap. VIII. LAUGHTER. 201 



mouth is acted on exclusively by the great zygomatic 

 muscles, which serve to draw the corners backwards and 

 upwards; but judging from the manner in which the 

 upper teeth are always exposed during laughter and 

 broad smiling, as well as from my own sensations, I can- 

 not doubt that some of the muscles running to the upper 

 lip are likewise brought into moderate action. The 

 upper and lower orbicular muscles of the eyes are at the 

 same time more or less contracted; and there is an inti- 

 mate connection, as explained in the chapter on weep- 

 ing, between the orbiculars, especially the lower ones, 

 and some of the muscles running to the upper lip. 

 Henle remarks 10 on this head, that when a man closely 

 shuts one eye he cannot avoid retracting the upper lip 

 on the same side; conversely, if any one will place his 

 ringer on Iris lower eyelid, and then uncover his upper 

 incisors as much as possible, he will feel, as his upper 

 lip is drawn strongly upwards, that the muscles of the 

 lower eyelid contract. In Henle's drawing, given in 

 woodcut, fig. 2, the musculiis malaris (H) which runs 

 to the upper lip may be seen to form an almost integral 

 part of the lower orbicular muscle. 



Dr. Duchenne has given a large photograph of an old 

 man (reduced on Plate III. fig 4), in his usual passive 

 condition, and another of the same man (fig. 5), nat- 

 urally smiling. The latter was instantly recognized by 

 every one to whom it was shown as true to nature. He 

 has also given, as an example of an unnatural or false 

 smile, another photograph (fig. 6) of the same old man, 

 with the corners of his mouth strongly retracted by the 

 galvanization of the great zygomatic muscles. That 

 the expression is not natural is clear, for I showed this 



10 Handbuch der System. Anat. des Menschen, 1858, 

 B. i. s. 144. See my woodcut (H. fig. 2). 



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