324 



- SCIENCE. 



[N. S. Vol. IX. No. 218. 



ments of a branchial arch to disappear, not 

 being developed even in tailed amphibians, 

 and it will be safe to call the lower portion 

 of the posterior arch of the hyoid a cerato- 

 branchial, and the adjoining segment an 

 epibranchial. The anterior pair of bones, 

 in the body of the tongue, C, are naturally 

 ceratohyals. 



Fig. 1. 



Hyoid of Grebe showing 

 component bones, much en- 

 larged. 



A First basibranohial. 



B Second basibranebiah 



C Ceratohyals. 



D Ceratobranobials. 



E Epibranehials. 



1 Basibranohial : Par- 

 ker. 

 Basihyal : M i v a r t, 

 Gadow, B e d- 

 dard-flgure. 

 f Basibranohial 2 : 

 I Parker. 



B \ Urohyal : M i v a r t, 

 I Gadow. Bed- 



L dard. 

 f Ceratohyal : Parker, 

 I Mivart, Gadow, 



C -I Beddardinpart. 



Basihyal : Beddard 

 [ in part. 

 C Ceratobranchial : 

 I Parker. 



I Thyrohyal : Mivart. 

 D -j Basibranohial : 

 I Gadow. 



Hypobranchial : 

 l Beddard. 

 f Epibranchial : 

 I Parker. 



E \ Ceratobranchial : 

 I Gadow, B e d- 

 [ dard, 



The next question, that of the proper 

 name for the anterior basal bone of the 

 hyoid, A, calls for some reflection, since it 

 involves not onlj^ the nomenclature of the 

 hyoid in birds, but in mammals as well. 



This bone is called basibranohial by Parker 

 and basihyal by Gadow, this latter name 

 being ordinarily used for the basal bone of 

 the mammalian hyoid. 



A true basihyal, or as it is better called 

 from its relations, glossohyal, is found in 

 fishes at the upper, anterior portion of the 

 hyoid apparatus. It is also present in tur- 

 tles, where it has the same relation to tb© 

 tongue as in fishes, and where it ossifies 

 some little time after the first basibranohial, 

 with which it soon becomes confluent. It 

 seems a little doubtful if a true basihyal 

 occurs among birds, although the median 

 piece of cartilage contained in the fleshy 

 portion of the tongue and articulating with 

 the fused cei'atohyals in such birds as 

 ducks may represent this bone. The ques- 

 tion is one which the embryologist can 

 readily answer. As pointed out by Parker, 

 the true basihyal does not occur in mam- 

 mals, the term being given to a bone that 

 is morphologically the first basibranchial. 

 It would seem that exact morphological 

 nomenclature should reject the term basi- 

 hyal for the first basal median bone in the 

 hyoid of birds and mammals, including, of 

 course, man, as there is no reason why hu- 

 man anatomy should stand as a stumbling 

 block in the way of the student of com- 

 parative anatomy, although it has often 

 done so. 



F. A. Lucas. 



SCIENTIFIC BOOKS. 

 A Treatise on Universal Algebra. By A. N. 

 Whitehead, M.A., Fellow and Lecturer of 

 Trinity College, Cambridge. Cambridge, Uni- 

 versity Press ; New York, The Macmillan Co. 

 Vol. I. Pp. xxvii + 586. Price, $7.50. 

 By ' Universal Algebra ' is meant the various 

 systems of symbolic reasoning allied to ordinary 

 algebra, the chief examples being Hamilton's 

 Quaternions, Grassmann's Calculus of Exten- 

 sion and Boole's Symbolic Logic. The present 

 volume contains an exposition of the general 

 principles of universal algebra, followed by a 



