528 THE SOLIDS. 



question, by means of a firm dense film of tissue, having a 

 fibrous character, and the fibres of which run lengthwise in 

 the groove, and are intimately united to it, especially along 

 the projecting rim. From this cochlear ligament, the coch- 

 learis muscle passes to the margin of the membranous zone, 

 filling the groove and projecting into the canal, so as to assist 

 in dividing the tympanic and vestibular scalae from one 

 another, and thus forming, in fact, the most external or the 

 muscular zone of the spiral laminse. Thus the cochlear 

 muscle is broad at its origin from the groove of bone, and 

 slopes above and below to the thin margin in which it termi- 

 nates, so that its section is triangular, and it presents three 

 surfaces, one towards the groove of bone, and one to each 

 of the scalae. The surface towards the vestibular scala is 

 much wider than that towards the tympanic scala, and pre- 

 sents, in a band running parallel to and at a short distance 

 from the margin of the membranous zone, a series of arched 

 vertical pillars with intervening recesses, much resembling 

 the arrangement of the musculi pectinati of the heart. (Plate 

 LXIX. fig. 5.) These lead to, and terminate in, the outer 

 clear belt of the membranous zone, which forms a kind of 

 tendon to the muscle. This entire arrangement is almost 

 sufficient of itself to determine the muscular nature of the 

 structure. If its fibres were of the striped variety, no doubt 

 would remain ; but its mass, evidently fibrous, is loaded with 

 nuclei, and filled with capillaries, following the direction of 

 the fibres, and in almost all respects it has the closest simi- 

 larity to the ciliary muscle of the eye. 



" The capillaries of the ciliary muscle are derived from 

 vessels meandering over the walls of the scala before en- 

 tering it, and those from above and below do not anastomose 

 across the line of attachment of the membranous zone ; thus 

 indicating that the continuation of this zone enters as a plane 

 of tendon into the interior of the muscle, dividing it into two 

 parts, and receiving the fibres in succession. 



" The scalae of the cochlea are lined with a nucleated 

 membrane, or epithelium, which is very delicate and easily 

 detached, usually more easily seen in the vestibular than in 



