60 LABORATORY OUTLINE OF NEUROLOGY 



General somatic afferent: 



Exteroceptive (general cutaneous) yellow 



Proprioceptive (muscle sense, etc.) and all afferent 



cerebellar connections orange 



Special somatic afferent: 



Vestibular (special proprioceptive) brown 



Auditory (cochlear) and optic green 



General and special visceral afferent (afferent sympa- 

 thetic connections, gustatory and olfactory) red 



General visceral efferent (pre- and post-ganglionic 



sympathetic fibers) purple 



Special visceral efferent light blue 



Somatic efferent, including all efferent cerebellar tracts dark blue 



Correlation tracts black 



Do not ink the drawings at first, but indicate the outlines of 

 tracts, etc., lightly in pencil; then, when all the sections have 

 been studied as directed in Sections 63 to 101, and the necessary 

 corrections made, review each section and enter upon its draw- 

 ing any additional details desired, such as the positions of gray 

 centers, nerve-roots, correlation tracts, etc. See that each draw- 

 ing is fully labeled. Finally, the drawings may be inked in if 

 desired. (For another illustration of this method of labora- 

 tory drawing, see Lineback, 1917.) 



Throughout the study of the microscopic cross-sections keep 

 in mind the external form of the brain in the region studied and 

 constantly refer to the intact human brain for the relations of 

 the nerve-roots and other external landmarks. 



(During the examination of these sections it will be helpful for 

 the instructor to demonstrate with the projection lantern all of 

 the sections to be studied and point out some of the more impor- 

 tant structures. Individual tracts should be followed through 

 the series of sections, passing the entire series in review many 

 times for this purpose.) 



4. Internal Structure of the Spinal Cord 

 63. General histology of the neuron. — (a) Procure from the 

 slaughter-house a portion of the spinal cord of a freshly killed 

 beef (the cord of any other one of the larger mammals will 

 answer). Each student should dissect out a small portion of the 

 substance of the ventral gray column (ventral horn) and tease it 

 out with needles on a clean glass slide until it is spread in a thin 

 layer. Cover the fresh tissue with a few drops of a solution of 



