ENCEPHALON OF REPTILES. 



'291 



functions of organic life. In the active state of the summer 

 season, suoli mutilation is followed by death in one or two hours, 

 rarely more.' 



In serpents, the cerebellum, fig. 188, c, ex])ands into a depressed 

 semicircular lobe directed backward from the confluence of the 

 restiform crura and overlapping tlie major part of the fourtli 

 ventricle, which appears as a short median fissure. The optic 

 lobes, ib. b, now expanded 

 to the breadth of the cere- 

 bellum, show both a longi- 

 tudinal and a transverse 

 fissure, the latter crossing 

 near the hinder Ijorder, and 

 giving to this j^art of the 



, brain a close resemblance 



■ to its homoloijue the ' biffe- 



|| minal bodies ' in Mammals. 



' The optic lobes are hollow : 

 the cerebral crura show 

 sliijht enlargements, like 

 optic thalami, anterior to 

 the optic lobes, before ex- 

 i:ianding into the hemi- 

 spheres. These are pressed 

 into close contact medially, 

 and comjDOse a prosence- 

 phalon nearly as broad as 

 long, and double the 

 breadth and length of the 

 mesencephalon. The outer 

 svirface of the hemisjiheres 

 is smooth, composed of a 

 thin layer of vascular or 

 grey neurine. Into their 

 cavity or ventricle a ' cor- 

 pus striatum' projects from 

 the under and outer side ; beneath or raesiad of which is a minor 

 prominence. The septum, formed by the thin mesial wall of 

 each hemisphere, is perforated for tlie passage of a ' clioroid 

 plexus.' The ventricles are continued forward into the olfactory 

 lobes, fig. 188, 1 ; each is marked off by an oblirpie fissure from 

 the fore part of the hemisphere, which it equals in breadth ; 



' CCI. 

 u 2 



ll Nihls III B i( uslnit 1 I IV 



