vi PREFACE. 
capable of farther development. The only purpose of a name 
is that it shall furnish a key to a common understanding; 
where the BNA name does not furnish such a key to English 
readers, and where there is a term in established English usage 
that does serve this purpose and seems unlikely to be sup- 
planted, we have used the latter. But we have endeavored to 
make the number of these exceptions as small as possible, and 
in such cases we have usually cited at the same time the term 
proposed by the German society, followed by the abbreviation 
BNA. When, on the other hand, we have adopted a BNA 
term for which there is also a commonly used English equiva- 
lent, the latter has likewise usually been cited in parenthesis. 
In deciding whether or not to use in a given case the BNA 
term many difficult cases arose. Will the common English 
name zznominate bone (os innominatum) be replaced by the 
BNA term os cox@ or coxal bone? We have held this to be 
highly improbable, and have therefore used the term zznomz- 
nate bone, merely citing os core (BNA)as a synonym. In the 
same way we have used centrum as a designation of a part ofa 
vertebra, in place of corpus (BNA); premaxillary bone or pre- 
maxilla in place of os zncisivum (BNA); malar bone in place 
of os zygomaticum (BNA); trapezoid as a name of one of the 
bones of the carpus, in place of os multangulum minus (BNA), 
etc. In other cases where it has seemed probable that the 
BNA term would come into common use, though now un- 
familiar, this and the more common English expression are 
both used or used alternatively; such has been the case, for 
example, with the Gasserian ganglion or semilunar ganglion 
(BNA). In naming the cerebral sulci and gyri the system in 
use for man is not well fitted for bringing out the plan of those 
in the brain of the cat, so that it was necessary to reject the 
BNA names for these structures. 
As to the use of the Latin terms and their equivalents in 
English form, we have made a practice of employing in the 
text sometimes one, sometimes the other; this has the advan- 
tage of giving variety, and of impressing the interchangeability 
of the Latin and English forms on the mind of the student. 
Where a given structure is called by two equally well-known 
