1881.] ^^^ [Wilder. 



it not better to adopt the very term employed by the Greeks to signify the 

 middle, meson, to /jjaov. equivalent to the more ponderous Latin meditul- 

 liumf The corresponding adjective is mesal, and the adverb mesad, while 

 in combination it becomes meso. 



The following general terms were also proposed by Barclay, and have 

 been more or less systematically employed by Owen, Huxley and others : 

 Dorsal, ventral, dextral, sinistral, lateral, with the corresponding adverbial 

 forms dorsad,* etc. Should the alleged correspondence of the ventral 

 region of the Vertebrate with the tergal region of the Arthropod prove to 

 be one of true homology, it may he desirable in time to discard dorsal 

 and ventral for more suitable terms, but for the present, if on practical 

 grounds alone, it seems well to retain them. 



Barclay proposed atlantal and sacral for the designation of the position 

 of parts lying toward the head or the tail, in reference to an imaginary 

 plane dividing the trunk at the middle of its length. But these terms were 

 not applicable to parts beyond the atlas and the sacrum, so that new 

 words were applied to the regions of the head. Perhaps this needless 

 complication has hindered the general adoption of Barclay's nomenclature 

 nothwithstanding its many admirable features. At any rate, cephalic and 

 caudal are much more acceptable terms, and are practically unobjection- 

 able, although certain theoretical difficulties readily suggest themselves. 



Proximal and distal, central and peripheral are in common use, and the 

 general employment of their inflections and derivatives is only a question 

 of time. Proximal and distal seem to be more applicable to the limbs and 

 their segments, while central and peripheral may be employed for vessels 

 and nerves. 



Ental, and ectal were proposed (9) as substitutes for the more or less 

 ambiguous words inner and outer, interior and exterior, deep and superficial, 

 profound and sublime. Derived respectively from b/ro:; and i-/.T6q their 

 significance is obvious, while their brevity and capacity for inflection will 

 probably commend them to accurate working anatomists. 



The Names of the Parts — Organonojiy. 



abbreviations of the more general names op encephalic parts. 



Ar. — Area. F. — Pissura. Px. — Plexus. 



C. — Coelia. Fm. — Foramen. R. — Recessus. 



Clm. — Columna. Fn. — Funiculus (root- Rx. — Radix. 



Cn. — Canalis. let). SI. — Sulcus. 



Cp. — Corpus. Fs. — Fossa. Spt. — Septum. 



Cr. — Crus. Inc. — Incisura. T. — Tuber. 



Crs. — Crista. L. — Lobus. Tr. — Tractus. 



Cs. — Commissura. LI. — Lobulus. Tl. — Tela. 



Em. — Eminentia. Pt. — Portio. 



*In his recent paper {2) on tlie Evolution ot Mammals, as printed in "Na- 

 ture," Jan. 6, 1881, p. 228, Huxley uses the term dorsad. 



