134 THE BRAIN OF REPTILES 



The Olfactory Lobes, comparatively small in size, are 

 found in front of, and partly beneath, the cerebral lobes 

 (fig. 66, i). They are true outgrowths from the cerebral 

 lobes, and the cavity within each of them is continuous 

 through its peduncle with that of the corresponding 

 ventricle. Each ' lateral ventricle ' is, in fact, prolonged 

 into the olfactory ganglion of the same side. 



Looking to the general characteristics of the Brain in 

 Birds, we find that the Cerebral Lobes and the Cerebellum 

 have attained a much greater development than is to be 

 met with among Fishes and Rep- 

 tiles ; while the relatively smaller 

 Optic Lobes are displaced down- 

 wards and outwards, as though 

 from the pushing forwards of the 

 cerebellum. The several parts of 

 the Brain are no longer in serial 

 order, and in the same horizontal 

 plane with the Spinal Cord. The 

 greatly increased weight of the 

 FIG. 67.-Brain of Sea ami organ as a whole, in comparison 



(Owen, after Anderson.) a, Cere- w ith that of the COl'd and of the 



bral hemispheres ; b, optic lobes ; . 



c, cerebellum ; d, spinal cord. entire body, are also seen to be 

 marked features, distinguishing the 

 Brain in Birds from that of lower Vertebrates. 



The Visceral Nervous System in Lower Verte- 

 brates. As an addition to this account of the Cerebro- 

 Spinal Axis in Fishes, Amphibia, Reptiles, and Birds, 

 a word or two may here be appropriately said in regard 

 to the Visceral System of Nerves met with in these 

 animals. 



We saw reason to believe (p. 110) that impressions 

 emanating from the Viscera constitute au important part 



