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Show 86 ON OLASSIFICA'l'ION. d f the more highly organized classes of the lower group, an o . . d. · · •tl wi11·ch he was so well acquainted, remain as ho lVlSlODS, \Vl l . . left them ; while the lower groups, of whiCh he knew least, and which he threw into one great heterogenous assen1blage,-the Radiata,-have been altogether remodelled and rearranged. l\iilne-Edwards demonstrated the necessity of removing tho Polyzoa from the radiate mob, and associating them with the lower Mollusks. Frey and Leuckart demonstrated the subregnal distinctness of the. OCElenterata. Von Sie1o1d and his school separated the Protozoa, .and others h~ve. complet~d the work of disintegration by erecting the Scolec~da 1nto a pnmary division, of Vermes, and making the Echinoder1nata into another. Whatever form the classification of the Animal Kingdom may eventually take, the Cuvierian Radiata is, in my judgment, effectually abolished: but the term is still so frequently used, that I have marked out those classes of which it consisted in the diagram of the Animal Kingdom (p. 6), so that you may not be at a loss to understand the sense in which it is employed. ON ~ri-IB CLASSIFICA'riON Oli' ANIMALS. 'l'HE SUBDIVISIONS OF THE MA.l\'IMAL£A LAHGEH 'l'HAN ORDERS. IN my last ler.ture I endeavoured to point out the grounds upon which naturalists have arrived at the conclusion that tho classes of the Ani1nal Kingdom may be arranged together in larger groups or divisions, such as have been termed "provinces" and "sub-kingdoms." If the time at my disposal for the consideration of Classification permitted me to do so, I should now, in the logical order of my discourse, take the opposite course; and turning again to the list of classes, I should endeavour to indicate in what manner they must be subdivided into sub-classes, orders, and lesser divisions. But it is needless to say that such a task as this would require many lectures, while I have only one to dispose of; and I propose to devote that one to a consideration of the classification of that class, which is in n1any respects the most interesting and the most important of any in the Animal I{ingdom,-the class MAMMALIA. A great many systems of classification of the Mammalia have been proposed, but, as any one may imagine from the nature of the case, only those which have been published within the last forty or fifty years, or since our knowledge of the anatomy of these animals has approached completeness, have now any scientific standing-ground. I do not propose to go into the history of those older systems, which laboured more or less under the disqualification of being based upon imperfect know- |
