494 



COMPARATIVE PHYSIOLOGY. 

 Fxr. 



Pig. 354.— Diagrammatic horizontal section of a vertebrate brain CHuxley). The follow- 

 ing letters serve for both this figure and the one following. Mb, mid-brain. What 

 lies in front of this is the fore-l)rain, and what lies behind, the hind-brain. L. t, 

 the lamina terminalis; Olf, olfactory lobes; Hmp, hemispheres; Th. E, thala- 

 mencephalon; Pre, pineal gland; Py, pituitary body; FM^ foramen of Munro; CS, 

 corpus striatum; Th, optic thalamus; C6, corpora quadrigemina; CC, crura cere- 

 bri; ICd, cerebellum; PF, pons Varolii; ilfO, medulla oblongata; /, olfactorii; IL 

 optici; ///, point of exit from brain of motores oculornm; lY, of pathetic!; Yl, 

 of abducentes; Y—XIl, origins of the other cerebral nerves. 1, olfactory ven- 

 tricle; 8, lateral ventricle; 3, third ventricle; 4, fourth ventricle; +, iter a tertio 

 ad g^artum veniriciUum. 



and the main basal ganglia ; between the gray matter of the 

 convolutions on the same side, and between the latter and those 



Fig. 355. — A longitudinal and vertical section of a vertebrate brain (Huxley). Letters 

 as above. The lamina terminalis is represented by the strong black line between 

 .ii'^and3. 



