276 



ZOOLOGY 



SECT. 



plane. The corpora striata, or basal ganglia of the cerebral hemi- 

 spheres, are connected together, as in all Vertebrates, by an anterior 

 commissure (D, com, below, lower line), above which is another com- 



A 



ftin 



A/cd.cbl 



SfJ.cd 



& *V- 1 cb 



J m EZZ7 Med.cbl 



-Sfi.cd. 



. obi 



Fro. 946. Brain of Rana. A, from above ; B, from below ; C, from the side ; D, in longitudinal 

 vertical section. Cb, cerebellum; Cer. H, cerebral hemispheres; ch. pl.i l , anterior, and 

 ch. pin: 2 , posterior choroid plexus (removed in .4) ; com, commissures, the two in front the 

 anterior and hijijiocampal, the two above the superior or halicnular and the posterior ; Cr. C, 

 crura cerebri ; ])!, diencephalon ; for. M, foramen of Monro ; ?', iter, or aqueduct of Sylvius ; 

 inf, infundibulum ; Uleil. obi, medulla oblongata ; Olf. /, olfactory bulb ; opt. ch, optic 

 chiasma ; Opt. I, optic lobe ; o/it. c, optic ventricle ; pin, stalk of pineal body ; pit, pituitary 

 body ; Sp. cil, spinal cord ; v' A , third ventricle ; r 4 , fourth ventricle ; / X, cerebral nerves ; 

 ISp. '-'Up. spinal nerves. (From Parker's Practical Zooloyy. A C, after Gaupp ; I), from 

 Wiedersheim's Comparative Anatomy, after Osborn.) 



