84 Journal of Comparative Neurology. 



e. g. , the term peduncle, applied to the peduncles of the cere- 

 bellum, has also been used in another sense to indicate bundles 

 or tracts of fibers in both the cerebellum and the cerebrum, 

 which latter use can not come under the original meaning of the 

 term. Confusion would be avoided if those structures were 

 designated by terms which should mean what they are, bundles 

 or tracts of fibers. The needs of a progressive and scientific 

 comparative neurology demand terms which are appropriate and 

 not likely to be confounded. 



Principles of a Terminology . — 



1. Terms should mean something. 



2. They should be appropriate. 



3. They should be euphonious. 



4. They should be mononyms ; /. e., single word terms. 



5. They should, when possible, indicate a definite idea of 

 the morphologic or embryologic form or relation of the struc- 

 tures designated. 



6. The same term should not be used to designate two 

 different things either in the same brain segment or in different 

 segments. 



Morphologically the foldings in the cerebellum are prob- 

 ably homologous with those in the cerebrum and the same state- 

 ment is true for the fissures. But it does not seem advisable to 

 employ the same term for those structures in two different brain 

 segments. Therefore we shall designate a fissure of the cere- 

 bellum by the term sulcus, as proposed by Wilder, and an adjoin- 

 ing ridge by the term /"<?////';//. (137, p. 125.) 



hiconsistencies in old terms. — Peduncles. — For the purpose 

 of general and comparative morphology the writer would sug- 

 gest that it would be best to restrict the term peduncle to the 

 peduncles of the cerebellum, and to regard each peduncle as 

 containing at least three great fiber tracts : viz., (i) the cephalic 

 tract, (2) the ventral, or pontile tract, (3) the caudal tract. 

 These are called by Wilder respectively prepedimcle^ mediped- 

 uncUy and postpediincle. 



Vermis. — The term is both inappropriate, and ambiguous. 



