/ 2 The Cranial Nerves 



The compound names so well express the clinical features of the 

 disease that description is almost superfluous. The lips cannot seize 

 the solid food, nor prevent the fluids from flowing away, and, as they 

 are also helpless in vocalisation, speech is gravely affected. 



The tongue is either protruded in a weak and trembling manner 

 or else lies flaccid in the mouth. In the latter case the voice is still 

 further altered ; and, as neither the tongue within, nor the buccinator 

 (p. 67) without, can keep solid food between the molar teeth, mastica- 

 tion is much impaired and the early stage of deglutition weakened. 

 The facial expression is altered in a characteristic manner. 



The pharynx, moreover, cannot grasp such food as is conveyed to 

 it, and, in feeble attempts at swallowing, the food escapes again into 

 the mouth and perhaps from between the lips. The larynx being 

 thrown out of working order, the voice is still further altered and 

 weakened. 



In every case of Duchenne's disease all these nerves are not 

 equally enfeebled ; the features of the paralysis necessarily vary with 

 the order in which the nuclei of the nerves are affected (v. p. 56). 



THE EYELIDS AND CONJUNCTIVA 



The so-called tarsal cartilages are thin plates of fibrous tissue 

 which form the foundation, or stiffening, of the eyelids. Their extremi- 

 ties are connected with the nasal process of the superior maxillae 

 and with the malar bones ; one border is near the edge of the lid, and 

 the other is attached to the margin of the orbit. The posterior surface 

 of the upper lid may be examined by turning the lid inside out, over 

 a probe laid on the outer surface of the lid, along the upper border of 

 the cartilage, the patient looking down so as to slacken the oculo-pal- 

 pebral fold of conjunctiva ; the stiff cartilage then holds the lid in the 

 everted position. The expanded tendon of the levator palpebrae is 

 inserted over the front of the upper tarsal cartilage. 



Superficial to each cartilage is the (striated) orbicularis palpebrarum, 

 which is separated from the skin by a delicate fascia devoid of fat, and 

 which, therefore, is readily infiltrated in Bright's disease. 



The orbicularis palpebrarum is the sphincter of the lids. It 

 arises from the inner corner of the orbit, and from the tendo oculi. 

 From this the pale, but striated, fibres of its palpebral portion pass out- 

 wards between the skin and the tarsal cartilages. The fibres of the 

 orbital part of the muscle are darker and coarser, and, like the others, 

 blend at the outer part of the orbit, where, however, they have no 

 important connection with bone. And thus it happens that when the 

 muscle contracts the outer commissure of the lids is drawn inwards, 

 so that the lachrymal secretion may be washed towards the inner 

 corner of the orbit and to the puncta lachrymalia. (If you rest your 



