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, Ig) is a 

 fusiform sac, the inner 

 lining of which is raised 

 up into a network of 

 delicate ridges, having 

 the appearance of a 

 honeycomb ; these ridges 

 are much closer and 

 more numerous towards 



FIG. 981. Brain of Lacerta viridis. A, from above, with thp aritprinr than t,n- 

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



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

 vertical section, a. c. anterior commissure ; aq. s. aque- p , r -i 

 duct of Sylvius ; cb. cerebellum ; c. c. crura cerebri ; c. h. OI tne lung, 

 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 ; olf. 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 ; pty. pituitary body ; v3, diacoele ; 



The brain (Figs. 981 

 and 982) presents all 

 the parts that have 

 , , , u~ , been described in the 

 (From Parker's brain of the Frog 

 (p. 275), with some 

 minor modifications. The two cerebral hemispheres (parencephala) 

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



