THE IXTRIXSIC TOPONOMY. 23 



beneath the Columna vertebralis; in the natural attitude of man, it is 

 beneath the bifurcation of the trachea ; in the position in which both man 

 and quadrupeds are commonly dissected, the heart is beneath the sternum ; 

 finally, it may be said to be beneath the ribs or the MM. intercostales in the 

 sense of being covered by them. The single English word here means suc- 

 cessively ventrad of, caudad of, dorsad of, and entad of the organs on four 

 different sides of it. Whatever may be thought best by the writers of de- 

 scriptions for advanced students, we hold that the use of such terms in a 

 work expressly designed for beginners would be little else than a self-stulti- 

 fication of its authors and a mockery of its readers. 



38. The Intrinsic Toponymy. Following the suggestion of Bar- 

 clay, and the more or less consistent example of the other writers above 

 named, we shall wholly discard all terms which " contain an allusion to the 

 situation of different objects, as they stand with respect to the heavens and 

 the earth ;" and shall designate the aspects and regions of the body by terms 

 derived from names which have been applied to the parts themselves. Hence 

 we shall speak of the cephalic and the caudal ends or aspects or regions ; of 

 the dorsal and ventral aspects or regions ; and of the dextral and sinistral 

 aspects and regions. 



Such terms constitute a Toponymical Vocabulary which is based upon 

 intrinsic instead of purely extrinsic and accidental relations. 



39. Cephalic and Caudal. Barclay proposed the words 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 body at about the 

 middle of its length. 



In many of the lower vertebrates, however, there is no distinct atlas or 

 sacrum, and in any case these terms would not apply strictly to parts beyond 

 the bones in question ; hence Barclay devised for the head an entirely new 

 set of terms, inial, glabellar, etc. So far as we know, atlantal and sacral 

 occur only in the writings of Owen (A, III, 519) and Turner (1, 819). 



Thacher has employed (jf, 282 and 292) orad as both adjective and 

 adverb, but the correlative aborad, which might have been expected, has not 

 been observed by us in his papers. 



Cephalic and caudal are employed by Cleland (1), and are recommended 

 by Quain as stated above. Their signification is obvious, and practically 

 there seems to be no serious objection to their use, although it is possible to 

 imagine cases where some ambiguity might arise from the fact that each is 

 employed in two senses, the one relative, and the other absolute. For 

 example, in the absolute sense, only the vertebrae of the tail are caudal ; 

 but relatively, caudal may be used to designate one or more vertebrae in any 

 part of the series, which are situated nearer than others to the caudal end of 

 the body. So too, we may speak of the caudal aspect of the skull, or of the 

 cephalic members of the series of caudal vertebrae. 



