318 



ZOOLOGY 



SECT. 



Olf 



The spleen (Figs. 979 and 980, spl.} is a small red body lying in 



the mesogaster, near the 

 posterior end of the 

 stomach. 



Organs of Respira- 

 tion. A slit-like aper- 

 ture, the glottis, situated 

 behind the tongue, leads 

 into a short chamber, 

 the larynx, the wall of 

 which is supported by 

 cricoid and arytenoid 

 cartilages. From the 

 larynx an elongated 

 cylindrical tube, the 

 trachea, passes back- 

 wards on the ventral 

 side of the neck. Its 

 wall is supported by a 

 large number of small 

 rings of cartilage, the 

 tracheal rings. Pos- 

 teriorly the trachea bi- 

 furcates to form two 

 similar but narrower 

 tubes, the bronchi, one 

 entering each lung. The 

 lung (Fig. 979, 10) is a 

 fusiform sac, the inner 

 lining of which is raised 

 up into a network of 

 delicate ridges, having 

 the appearance of a 



m.o 



m.o 



" f f 



honeycomb ; these ridges 

 are much closer and 

 more numerous towards 



anterior than to- 



m.o 



FIG. 981. Brain of Lacerta viridis. A, from above, with 



the left hemisphere (c. h.) and optic lobe (o. 1.) opened. , , . , 



B, from beneath. C, from the left side. D, in longitudinal Wards the posterior end 



vertical section, a. c. anterior commissure ; aq. s. arjue- r ,-1 l lrnfr 

 I duct of Sylvius ; c b. cerebellum ; c. c. crura'.cerebri ; c. h. OI Tine lun. 



cerebral hemispheres ; ch. p. choroid plexus ; c. s. corpus 



striatum ; f.m. foramen of Monro ; inf. infundibulum ; 



m. o. medulla oblongata : o. c. optic chiasma ; o. I. optic 



lobes; nlf. olfactory bulbs with their peduncles or tracts ; 



o. t. optic tracts ; o. v. aperture between aqueduct of 



Sylvius and optic ventricle ; p. c. posterior commissure ; 



pn. pineal apparatus ; pttt. pituitary body ; v3, diacoele ; 



v4, metaco3le ; I Xll, cranial nerves. (From Parker's 



Zootamy,) . , 



(p. 275), with some 

 minor modifications. The two cerebral hemispheres (parencephala) 

 (Fig. 981, c.h.) are oval bodies, somewhat narrower in front than 



Q81 



982) presents all 



,, , , 

 parts tHat nave 



HptsrriViprl in flip 



brain of the Fro 01 



& 



and 



, 

 trie 



