522 THE SOLIDS. 



Plate LXVIII. fig. 10.) After death, this space is occupied 

 by a small quantity of fluid, the liquor Morgagni. 



Beneath this epithelium, again, other small oval granular 

 cells are encountered ; from these possibly the fibres of the 

 lens take their origin. 



The lens is of less density externally than internally ; this 

 is also one of the results of the peculiar form and arrangement 

 of the fibres. 



In the adult eye the lens is entirely destitute of blood- 

 vessels, although during its development in the foetus it is 

 copiously supplied with them. 



THE ORGAN OF HEARING. 



ELABORATE as is the organisation of the ear, it yet presents 

 less to interest the microscopical anatomist than many other 

 of the organs which enter into the composition of the human 

 fabric. The ear is divisible into three portions the limits 

 of each of which are well defined an external, a middle, and 

 an internal: the external portion is an apparatus for the 

 collection of sound ; the middle is designed for its convey- 

 ance to the internal or true and essential division of the 

 organ of hearing. 



The External Ear. 



The external ear consists of the expanded part or auricle, 

 and the external meatus. 



The auricle. The auricle presents several eminences and 

 depressions, many of which have received distinct names ; it 

 is made up of integument, cartilages, and fat ; the integu- 

 ment is thin and delicate, and is furnished with but few seba- 

 ceous glands ; the cartilages are of the fibrous kind, and are 

 three in number, the larger forming the pinna, being sepa- 

 rated from that of the tragus and antitragus, by grooves 

 filled up with fibrous tissue ; lastly, the fat is situated 

 chiefly in the lobe of the ear. Ligamentous bands bind the 



