xn. THE CRANIAL NERVES AND SPECIAL SENSE ORGANS 
Material. —The head 1 of the calf or sheep from which the brain 
was removed; whole heads sawn sagittally for demonstration of 
general topography; one or two sheep (or calf) skulls sawn hori¬ 
zontally and sagittally, and disarticulated skulls. For comparison 
with human relationships, models and demonstration dissections 
may be used. 
A. THE GENERAL TOPOGRAPHY OF THE HEAD. 
One-half of the heads may now be sawn by a median sagittal 
section into halves. After thoroughly washing the sawn surfaces 
under running water study these sections for general topography, 
identifying the various bones, noting relation of nasal cavities, 
mouth, superior and inferior regions of the pharynx, oesophagus, 
larynx; nasal septum, hard and soft palates, tonsils between the 
pillars of the fauces, tongue, epiglottis, and glottis; openings of 
auditory (Eustachian) tubes; location and character of teeth. 
Cf. with similar sections of the entire head, in which the cranial 
cavity containing the brain is also included; also with models of 
the human head, median sagittal section. Draw, labeling the 
parts identified. 
B. THE FLOOR OF THE CRANIAL CAVITY. 
Study the floor of the cranial cavity, first fitting together the 
two halves if the head has been sawn. Use for comparison the 
previous study of the features of the bony floor of the human 
cranial cavity (p. 44). Note that here the floor is covered by the 
dura mater, which does not conform completely to the bony floor 
of the cavity. This is particularly true in the region of the sella 
turcica, where a fold of the dura forms a false floor, the diaphragma 
sellae, beneath which the hypophysis, is located. The hollow 
stalk of the hypophysis, severed in the removal of the brain, may 
1 This, after two or three weeks in formalin, should be washed for two or three 
days in running water to remove the formalin, and may be kept in water during 
the progress of the work in the intervals when it is not being used. 
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