THE METHOD OF MAKING POST-MORTEM EXAMINATIONS. 



11 



terior lobes of the cerebrum are to be pulled gently backward, the 

 uerves, vessels, aud teutorium severed, and the medulla cut squarely 

 across, as low down as possible. The brain is now removed from the 

 cranium by passing the fingers of one hand down, beneath, and behind 

 the lobes of the cerebellum, and drawing the brain out, supporting the 

 convexity with the other hand. 



The adult brain in the male weighs on the average about 1,400 grams; 

 that of the female, about 155 grams less. The average proportional 



Fir,. 1. SIDE VIEW OF THE HUMAN BRAIN, SHOWING ITS FISSURES AND CONVOLUTIONS. 



weight of the brain to that of the body is about one-forty-fifth, although 

 in this, as in the absolute weight, there is considerable variation. 



The exact situation of any lesion which is apparent externally should 

 be described by its relation to the lobes, fissures, convolutions, and sulci 

 (Fig. 1). 



The brain is first laid upon its convex surface, and the anterior, mid- 

 dle, and posterior cerebral arteries, as well as the basilar and the 

 carotids, are to be examined for emboli, thrombi, atheroma, and aneur- 

 isms. Evidence of extravasations of blood, tumors, and inflammatory 

 lesions are now to be looked for. The brain is next turned over on to 

 its base. An incision is made through the pia mater, over the convex 

 surface of the cerebrum. The membrane is stripped up, and its adher- 

 ence to the brain and its thickness are noted. 



The more common method of opening the brain is as follows: The 

 halves of the cerebrum are to be separated until the superior surface of 

 the corpus callosum is exposed (Fig. 2). A longitudinal incision is 

 made through the junction of the corpus callosum and the cerebrum, and 

 downward into the ventricle. The incision should be made carefully, so 

 as not to cut through the ventricle into the ganglia below. The incision 



