BRR 



THE WINDPIPE AND LUNGS OF MAN. (From a specimen) 



TR, the trachea or windpipe, supported by gristly rings. It divides into 

 two bronchi (BR) entering the lungs (L). There they break up into finer 

 and finer bronchial tubes or bronchioles (BRR), ending in little dilatations 

 which are divided into chambers called "air-cells." On the walls of these 

 the interchange of gases takes place. To the left side, as diagrams go, the 

 lung is seen intact; to the right, partly dissected. 



cc 



CBL 

 A V 



SECTION OF A HUMAN BRAIN 



Nerves entering the brain. F is a longitudinal bridge of fibres, called the fornix. It makes 

 the roof of the optic thalami region, or third ventricle. Behind the fornix are seen two trans- 

 verse commissures cut across. CQ, the corpora quadrigemina or optic lobes. CH, the fore- 

 brain or cerebral hemispheres, showing internal indications of convolutions (CO). 



CBL, the cerebellum, with an internal pattern (AV) called the arbor vitee. This is due to 

 the folding of the nervous tissue into a number of lamella, which give off secondary plaits. 



SC. the spinal cord. CSC, the cerebro-spinal canal continued down the centre of the 

 spinal cord. 



P, the pons Varolii, a bridge forming a sort of transverse floor to the cerebellum. Behind P 

 is the "bulb" or medulla oblongata. 



PB, the pituitary body, a nervous and glandular body growing down from the floor of the 

 optic thalami region, or third ventricle. ON, the optic nerve. 



