SOME NEURAL TERMS. 137 



recommended that mononyms be preferred to polyonyms." 

 Calcar avis is a polyonym ; calcar is a mononym. 



If it be said that unguis is also a mononym, the answer is 

 that in this case " other things " would not be equal, because 

 (i) no general preference has ever been shown for it or for any 

 term of which it is a constituent; (2) there would be lost the 

 advantage of the correlation now existing between the ental 

 ridge and the fissure collocated therewith. 



Two objections might be offered to the omission of the 

 qualifying genitive, avis. 



(1) The original sense of the Latin calcar was spur, and its 

 application to the sharp projection on the leg of the cock was 

 metaphoric. This can hardly be entertained as a serious objec- 

 tion; indeed, although the modern spur has a toothed wheel or 

 rowel, the primitive instrument was little more than a spike; 

 hence the qualifying genitive is needless. 



(2) Calcar has also been applied occasionally to two other 

 parts, viz., the calcaneum (os calcis) and the styloid process of 

 the temporal bone. But (a) neither of these uses is sanctioned 

 by the German committee, and (b) even if they were, the con- 

 text would infallibly avert misapprehension (p. 113); indeed, 

 the German committee apply clivus without qualification to 

 features of two adjacent cranial bones, the occipital and 

 sphenoidal. 



Finally, the sufficiency of the mononymic substantive, calcar, 

 is practically conceded by all who employ the mononymic 

 adjective, calcarinus, in any of its Latin inflections, or in any 

 of its national paronymic forms. The simplest requirements 

 of logic present the following dilemma: If calcarimis is suffi- 

 ciently distinctive, so is calcar, from which it is derived. But 

 if calcar avis is essential, then the adjective should be calcari- 

 avianus or some such compound. See also under dtira. There 

 seems to have been little, if any, hesitation on the part of the 

 German committee in adopting fissura calcarina (His, '96, 170), 

 and no reason for the maintenance of calcar avis has yet come 

 under my notice. 



CHI ASM A vs. chiasma opticum. Meynert's chiasma nervi 

 acustici is not retained by the German committee, and, even if 



