44 LABORATORY OUTLINE OF NEUROLOGY 



through the medulla oblongata and pons. At least six levels 

 of the medulla oblongata should be studied, and more if 

 possible. Similar sections through the midbrain and thalamus 

 are also very desirable, though somewhat more difficult to 

 prepare (cf. Sheldon, '14). The student should also study as 

 many microscopic preparations as possible of special regions of 

 the brain and sense organs, particularly of the spinal cord and 

 the cerebral and cerebellar cortex, illustrating the appearances 

 of particular structures when prepared by the methods of 

 Weigert, Nissl, Golgi, Cajal, Marchi, etc. 



37. If microscopic preparations are not available, it will be 

 found practicable to select from the following paragraphs 

 those which apply to the gross material only (see Courses 

 I, III, IV, and V, pp. 11, 12). Gross transverse sections 

 through the human brain at the levels indicated in Section 62 

 will show many details of internal structure, including the 

 location of the principal gray masses and fiber tracts. In mak- 

 ing the gross sections the incisions should be made parallel to 

 each other and at right angles to the long axis of the medulla 

 oblongata as far forward as the midbrain (levels 1 to 9, Section 

 62) . In front of this region the cuts should no longer be made 

 parallel, but so inclined toward each other ventrally as to make 

 each slice somewhat wedge-shaped with the large end of the 

 wedge dorsal. In this way allowance is made for the flexure of 

 the cerebral hemispheres upon the midbrain and the plane of 

 section is kept approximately transverse to the curved long axis 

 of the brain. 



Even if microscopic sections through all or a part of the brain 

 stem are available, a brain should be prepared for demonstra- 

 tion purposes by gross section as described above to facilitate 

 the localization of the microscopic sections and their interpre- 

 tation in terms of the external form of the intact brain. 



If the laboratory work is limited to the study of gross mate- 

 rial alone, it is recommended that the student read also those 

 sections of the Outline which give directions for the study of 

 microscopic sections, and with the aid of the references given at 

 the close of each section consult in text-books and atlases 

 figures of corresponding sections. 



The primary purpose of this study is to gain an understand- 



