FRAMEWORK OF THE LARYNX. 37 



other parts by its softer nature, and by its containing a few 

 scattered cartilage cells. It usually appears to consist of fibro- 

 cartilage, but sometimes conceals a hyaline nucleus within the 

 fibrous cortex. 



Lastly, the central substance of the arytenoid cartilages 

 exhibits a purely hyaline structure. Near their surface, how- 

 ever, they frequently become fibrous, and this occurs without 

 exception at the point of attachment of the processus vocales 

 and at the apex of the pyramid. In the Dog a remarkable 

 development of cartilage may take place, extending to some 

 distance from the arytenoid cartilages into the two vocal cords. 

 In such cases a fibro-cartilaginous lamella of moderate width 

 runs forward in the cords, which is continuous with a mass 

 formed by the fusion of the cartilages of Santorini and Wris- 

 berg with the arytenoid cartilages. 



The mode in which the cartilages are united together so that 

 movement is combined with great resistance to displacement is 

 accomplished by means of ligaments or proper articulations. 

 The former are everywhere continuous with the surrounding 

 tissues, and are essentially composed of elastic with a few con- 

 nective-tissue fibres, and in infancy are especially rich in fusi- 

 form cells. Near their attachment to the cartilages they usually 

 contain cartilage corpuscles, which become more numerous 

 towards the cartilage, and ultimately a transition into carti- 

 laginous tissue occurs. 



An articular mode of union exists between the cricoid and 

 arytenoid cartilages, and between the cricoid and the thyroid 

 cartilages. 



The crico-arytcenoid articulating surfaces are composed of 

 hyaline cartilage, the somewhat small cartilage cells being 

 closely arranged, and lying with their long axes parallel 

 to the surfaces of the joint. The articular surfaces of the 

 cricoid become to some extent fibrous at their periphery, i.e. 

 at the line of attachment of the capsular ligament, the fibres 

 extending into the joint from all sides, but becoming lost before 

 reaching the centre. The capsule, on the other hand, contains 

 cartilage corpuscles near its point of attachment, which extend 

 into it from the cartilage. From behind and externally an in- 

 terarticular substance penetrates into the joint which presents 



