432 ANATOMICAL TECHNOLOGY. 



The candal regions of the hemispheres rest upon the bony ten- 

 torium (Fig. 59, 88, 552) ; note that the dura is continued upon 

 its surface and closely attached, but quite independent of it. 



Remove the supraoccipitale ( 1013), leaving the dura upon the 

 cerebellum if possible, and then the Crista lambdoidalis and the 

 parts of the parietalia between the latter and the attachment of 

 the ten torium. The latter may then be nipped at each side as 

 directed in 1103, and the central part removed. The tentorial 

 dura commonly adheres so closely that it must be removed likewise 

 by snipping it along the attached border of the tentorium. In 

 removing it, care must be taken not to injure or tear away the 

 conarium (PL II, Fig. 4, en.). The entire dura so far as exposed 

 may now be lifted as directed above. 



Remove more of the right side of the skull so as to expose the 

 Lobulus TiypocampcB (PI. I, Fig. 2, LI. Jimp.) ; the perioticum (Fig. 

 59, pro.) should be cracked with the nippers and removed in small 

 fragments. 



1112. Removal. Hold the head so that the right side of the 

 brain tends to fall out of place. The dextral nerves are to be di- 

 vided with the scissors or small scalpel, beginning with the most 

 caudal. If the hypophysis is to remain attached to the brain, the 

 division of the optic and trigeminus nerves should be deferred until 

 after it is dislodged or the bone is nipped from about it. Finally, 

 the sinistral nerves may be divided and the brain allowed to fall into 

 the brine. 



1113. With some modifications, the method just described is well adapted to the 

 removal of the brain from young human subjects. If the skull cannot be cut with the 

 nippers or bone scissors, it may be trephined in various places and the intervening areas 

 broken away. The dura should be retained as long as possible, and the entire head should 

 be floated in strong > brine so that the brain may not bear its own weight at all. If the 

 head is still attached to the body, the latter may be laid upon a box as high as the dish 

 BO that the head may hang over the side of the latter. 



'1114. (B) By Hemisection of the Head with a Saw. The advantages of this 

 method are : (1) It is comparatively expeditious ; (2) the skull may be preserved ; (3) the 

 brain may be hardened in situ, safely transported if desired and removed at a future time. 



The two following objections are more apparent than real : 



(1) The skull is " mutilated." On the contrary, for nearly all purposes of study, to 

 halve a skull is to double its value. Even if it is to be mounted with the skeleton or within 

 the skin, the two halves may be readily conjoined. 



(2) The brain is injured by the saw. If the hemisection is accurately mesal, the only 

 parts really destroyed are the conarium and crista ; all other parts which cross the meson 

 are recognizable, and the mesal aspects of the hemispheres are often untouched. If it be 



