EXUDATION. 



[ 300 ] 



EYE. 



bules, rarely of crystals ; earthy matters, 

 aiuorphous orcrvstalline ; various substances 

 derived from the food, as muscular fibre, 

 starch-granules, cellular tissue, Szc. ; ento- 

 zoa, or ffagments of them, as portions of the 

 cysts or hooks oi Echinococcus; infusoria and 

 alg\T?, as Monads, Bacteria, Sarcina, Sec ; 

 carbon and true pigment, either in the free 

 state or contained •vvithin epithelial cells ; 

 and fragments of pulmonary tissue. 



The aid of the microscope in the exami- 

 nation of the expectoration will occasionally 

 throw an unexpected light upon the dia- 

 gnosis of disease. And it 

 has been shown, that by 

 boiling- the sputa with 

 solution of caustic soda 

 and washing, the pulmo- 

 nary fibrous tissue may 

 often be detected in 

 Phthisis. 



EXUDATION, and 

 EXUDATION COR- 

 PUSCLES. See In- 

 flammation. 



EXU'VIUM (exuvia; 

 or exuvise, plur.). — The 

 cast or shed sldn of ani- 

 mals. The exuvium of 

 many minute animals ex- 

 hibits the form and struc- 

 tiu'e of the skin, and the 

 parts upon which it is 

 moulded, better than 

 these can be discerned 

 in the living animals, on 

 account of its transpa- 

 rence. The exuvium of 

 the Triton (PI. 49. fig. 

 12) exhibits the cellular 

 structure of the epider- 

 mis veiy beautifully. 



EYE.^ — From want of 

 space, we are compelled 

 to assume that the reader 

 possesses a knowledge of 

 the component parts of 

 the eye and their relative 

 position, as far as can be 

 obtained without the use 

 of magnifying glasses. 

 These parts are generally 

 described in works upon 

 anatomy, and in most of 

 those upon optics. 



The outer fibrous coat 

 of the eye is commonly 

 regarded as consisting of 



single continuous 



two parts : one anterior, smaller and trans- 

 parent — the cornea; the other, posterior 

 larger and opaque — the sclerotica. The 

 history of the development and the minute 

 structure of these prove that they must be 

 considered as forming a " 

 membrane. 



The cornea may be regarded as consisting 

 of three layers : — 1, the corneal conjunc- 

 tiva ; 2, the true cornea ; and 3, the mem- 

 brane of the aqueous humour. 



The corneal conjunctiva (tig. 207, C«) con- 

 sists of laminated soft epithelium — the 



Fig. 207. 



Section of the membranes of the eye, near the ciliary processes. 



Sc/., sclerotica ; C, cornea; Pr. eiZ., ciliary process ; C a, anterior chamber; 

 Cp, posterior chamber ; Cr, vitreous humour ; C. P., canal of Petit ; i, lens ; 

 I, iris : a, conjunctiva of the cornea — epithelial layer; b, subjacent elastic layer ; 

 c, fibrous layer of the cornea; </, membrane of the aqueous humour; e, its 

 epithelium ; y, end of the membrane and its fusion with the fibres ,9, which 

 pass to the iris at i. forming the pectinate ligament; h, venous canal; k, 

 ciliary muscle arising from the inner wall I of the venous canal ; m, pigment- 

 layer of ciliary process^es; n, that of iris ; 0, fibKius layer of iris ; p, its epi- 

 theUum; 5, anterior wall of capsule of lens; s, ep'theliimi of capsule ; ^ ante- 

 rior thickened portion of hyaloid membrane ; «, zonule of Zinn, or anterior 

 lamina of hyaloid membrane; v, posterior lamina of the same; «■, colourless 

 epithelium of the ciliary processes ; ?r', anterior end of this epithelium ; 

 X, conjunctiva of sclerotica ; z, posterior wall of the capsule of the lens. 



Magnified 12 diameters. 



