94 REVIEWS. 



erroneous impressions ? In the grouping of the animals considerable taste 

 has been displayed. 



In general, the selection of the species which are to serve as types 

 of the group or order to which they belong is judiciously performed. 

 This, however, is not always the case. Thus, of the numerous division of 

 Edriophthalmatous Crustacea no species is shown, while four figures of 

 Entomostraca are given. 



But how has Mr. Patterson succeeded with regard to the second 

 object which he proposes to accomplish ? Has he been able to present the 

 student with a correct and characteristic outline of the animal kingdom, ac- 

 cording to the views of modern zoologists ? To perform this satisfactorily 

 is no easy task. Zoology is from its nature a progressive science, and 

 whatever arrangement may be determined on is liable to receive more or 

 less alteration from the new relations which some fresh discovery may 

 suggest to the philosophic naturalist. But let us inquire what are the ob- 

 jects which a well-devised system of zoological classification proposes to effect. 

 " The natural history of an animal (says Cuvier) is the knowledge of 

 the whole animal/' But such a knowledge, though most essential, is still 

 insufficient. It has been well said, that " in the several tribes of organised 

 beings we have not a mere aggregation of individuals, each formed upon 

 an independent model, and presenting a type of structure peculiar to itself; 

 but that we may trace through each assemblage a conformity to a general 

 plan, which may be expressed in an 'archetype' or ideal model, and of which 

 every modification has reference either to the peculiar conditions under 

 which the race is destined to exist, or to its relations to other beings. Of 

 these special modifications, again, the most important themselves present 

 a conformity to a plan of less generality ; those next in order to a plan of 

 still more limited extent, and so on, until we reach those which are pecu- 

 liar to the individual itself. This is, in fact, the philosophical expression 

 of the whole science of classification."* 



The systems adopted in the present day are, more or less, modifications 

 of that of Cuvier. Since the time when that system was promulgated 

 very many discoveries have, however, been made, which must considerably 

 alter our views of the Cuvierian arrangement. Too^hastily to adopt all the 

 innovations which have been suggested would, indeed, be injudicious ; but, 

 still, we may regard one great fact as having been clearly established — 

 namely, that there exist five very distinct plans of structure, or " types," 

 to some one of which any animal form (taking into account, likewise, its 



* Carpenter's Comparative Physiology, p. 10. 



