5. Cut through the spinal cord behind the medulla, and the cranial nerves within 



the skull ; carefully remove the brain with the handle of a scalpel, and 



examine and sketch the ventral surface, indicating — 

 (a) The cerebral hemispheres. 

 (6) Optic chiasma. 



(c) Lobi inferiores beneath the optic thalami. 



(d) Pituitary body (hypophysis cerebri) and infundibulum. 



(e) The three lobed saccus vasculosus. 



(/) The crura cerebri and the anterior portion of the medulla oblongata. 



6. Lift up the cerebellum and note the cavity of the 4th ventricle covered by a 



delicate vascular membrane. Note between the optic thalami, and covered by 

 the pia mater, the cavity of the 3rd ventricle. Cut open the optic lobes 

 and mesencephalon to expose the aqueductus Sylvii connecting the 3rd and 

 4th ventricles. 



7. Cut across the cerebral hemispheres, and note that there are no lateral ven- 



tricles. 

 F. Examine the eye of the left side. 



1. Note its external characters, viz. : — 



(a) Its elongated and depressed form. 



(b) The absence of eyelids. 



(c) The cornea forming the front of the eyeball. 

 Id) The pupil. 



(e) The pigmented iris, with a fringe hanging downwards from its upper 

 margin. 



2. Dissect off the skin and note — 



(a) The cartilaginous sclerotic covering the posterior two-thirds of the eye and 



continuous with 

 (6) The transparent cornea covering the anterior portion. 



(c) The superior oblique muscle attached to the upper anterior portion of the 



eyeball, and passing to the anterior part of the orbital cavity. 



(d) The superior rectus muscle attached to the upper posterior portion of the 



eye. 



(e) The internal rectus muscle immediately in front of the superior rectus, 



passing beneath the superior oblique, and attached to the anterior portion 



of the eye. 

 (/) The external rectus muscle attached to the posterior part of the eye and to 



the orbital cavity immediately behind the superior rectus. 

 (g) The inferior oblique muscle attached to the lower anterior portion of the eye. 

 (h) The inferior rectus muscle inserted into the lower portion of the eye. 

 (*) The cartilaginous peduncle articulated by its inner end to the skull and 



by its outer to the eyeball. 

 Make a sketch of the eyeball with the muscles attached. 



3. Cut open the eye transversely near the junction of the sclerotic and cornea, 



and note — 

 (a) The aqueous humour between the iris and cornea. 

 (6) The crystalline lens. 



(c) The black choroid coat lining the interior surface of the sclerotic. 



(d) The iris continuous with the choroid and the aperture (pupil) in its 



centre. 



(e) The vitreous humour filling the posterior chamber of the eye. 



(/) The retina lying within the choroid and covering the posterior portion of 



the eye. 

 Make a sketch showing an ideal section of the eye. 



