546 



suggested, though from its position in the jaw I incline to the former 

 view. 



If pm^ of the Marsupials has a successor belonging to a different 

 dentition as is generally stated, but upon which some doubt is cast 

 by Woodward's researches on the development of the teeth in the 

 Macropodidae (15), may not some light be thrown on this point by a 

 study of the condition in the Dog, which might be diagrammatically 

 represented in this way. 



If the last deciduous premolar belongs to the true molar series, 

 as I believe, an explanation will be found of the very curious and 

 anomalous condition found in the Dog. At the same time it will render 

 it impossible to say oif-hand, without careful microscopic examination, 

 which teeth belong to the milk and which to the permanent dentitions, 

 and as a consequence of this, a revision of the terminology will be 

 rendered necessary, and to do this I think numbering the dentitions 

 from without inwards will be the least open to objection. 



In conclusion I would like to thank my friend Mr. Charters 

 White for kindly photographing the sections for this paper. I have 

 made use of photographs rather than drawings, as in the latter it is 

 difficult to restrain personal bias from accentuating facts, however de- 

 sirous one may be of arriving at the truth. 



9 



10 

 11 



12 

 13 

 14 

 15 



Bibliography. 



Leche, Morph. Jahr., 1892 and 1893. 



Kükenthal, Jen. Zeit. f. Naturw., XXVIII. 



RösE, Archiv Mikr. Anat., XXXVIII. 



Woodward, M. F., "On the development of the teeth of certain In- 



sectivora", British Assoc, 1895. 



Leche, Morphol. Jahrbuch, Bd. XX, 2. Heft. 



Woodward, Science Progress. July 1894, p. 438. 



Leche, Zur Entwickelung des Zahnsystems der Säugetiere, 1895. 



KtJKENTHAL, Anat. Anzeiger, Bd. 6, No. 23 und 24. 



— , ebenda, Bd. 10 (1895) p. 653—659. 



Pabker, W. N., Proc. Zool. Soc. Lond., 1882. 



CuviER, Ossements fossiles, 1837. 



Nawroth, "Zur Ontogenese der Schweinemolaren" 1893. 



Hoffmann, Zeitschr. f. wiss. Zool., Bd. 58 (1894) p. 566—617. 



WiF.DEKSHEiM, Structurc of Man (Eng. Trans.) p. 160. 



Woodward, "On the development of the teeth of the Macropodidae", 



P. Z. S. Lond., May 1893. 



