158 Zoological Collections. 



4ithlt/f The teeth termed milk-fangs by Sir E. Home in his 

 paper on this subject in the Philosophical Transactions ^ can- 

 not be temporary teeth, because they are found in the head of 

 an apparently adult specimen, or a least in a head larger, heavi- 

 er, and denser considerably than another, which, having the 

 tusks formed like those described as permanent by Sir E. Home, 

 must be considered as an adult specimen; and because there 

 are not the slightest appearances of any approaching change 

 in the form of the tooth, or indicative of the approach of an- 

 other or permanent tooth. Dr Knox considers them therefore 

 as permanent teeth^ not as temporary ; and to reconcile these 

 contradictory statements on the part of anatomists, he supposes 

 it not unlikely that the differences in the form of these tusks 

 may originate not in a difference of age, but in their belong- 

 ing to distinct varieties or species of the Dugong. 



% Baron Ctwier'*s great work on Fishes.* 



Two volumes of this work, for which the celebrated author 

 has been collecting materials for upwards of forty years, have 

 appeared. The first volume contains a historical view of the 

 progress of Icthyology, drawn up with all the critical accu- 

 racy which the most intimate knowledge of the subject, and of 

 the original writers on it enabled him to display, from the 

 earliest notices of this class of animals among the Egyptians, 

 Phenicians, and Carthaginians down to the present time. Then 

 follows the different scientific classifications which have been 

 proposed ; a general idea of the nature and organization of 

 Fishes, and minute details of their external and anatomical 

 characters. This volume is accompanied by nine plates in folio, 

 to illustrate the anatomical details; and as the common Perch 

 is one of the fishes most extensively diffused over the world, 

 and belongs to by much the largest group of fishes, the Jca7i- 

 thopterygii, it has been adopted as the example most easily ac- 

 cessible for detailing the leading external and internal charac- 

 ters of the class. We may return to the contents of this vo- 

 lume for some of the interesting information it includes ; but 



• Hisioire Naturelle des Poissons, par M. le Baron Cuvier et M. Valen- 

 ciennes, vols, i and ii. Paris, 1828. 



