5188 Notices of New Books. 



harmonise all of them, we can form no idea of Nature's system. This 

 principle of a plurality of affinities, of the radiation, so to speak, of 

 affinities, must be the ground-work for the association of all groups 

 higher than species ; and this Mr. Wollaston seems entirely to ignore. 

 Let him speak for himself. 



" There can be no doubt that amongst a large class of ordinary ob- 

 servers a clear perception of the generic system in an abstract sense 

 does not by any means prevail. What the nature of a genus really is, 

 would appear to have been very commonly overlooked, or perhaps 

 misunderstood by people of this stamp : and the consequence has 

 been that the wildest notions have frequently arisen, even from men 

 of sound specific attainments, as to the claims (for annihilation or 

 retention as ' genera ') of certain subsidiary zoological assemblages. 

 The terms l genus' and 'species' have been conjointly so long asso- 

 ciated in our minds with the self-same things (whatsoever they may 

 be), that they have become almost part and parcel of the objects 

 themselves) ; so that the student who does not sufficiently reflect on 

 their true signification is apt to regard them as of equal importance, — 

 or, rather, more often perhaps than otherwise, to make the latter sub- 

 servient (or inferior) to the former ! This however is, in reality, the 

 very reverse of what should be the case, as a moment's consideration 

 will indeed at once convince us : for what are genera, after all, but 

 dilatations (as it were) along a chain which is itself composed of sepa- 

 rate, though differently shaped links ? The links (or the actual, 

 independent bodies which constitute the chain) are the species; but 

 the knobs, or swellings, which their several forms may tend, by de- 

 grees, to establish along its course (through the slightest disparity 

 which each of them presents from that which is next in succession to 

 it; and therefore through the gradual manner in which the bulbs or 

 nodules may be said on the whole to be produced), are the groups into 

 which those species naturally fall. It matters not a straw whether 

 these assemblages be primary, secondary, tertiary, &c, — in other 

 words, whether they be departments, families, or genera, as usually 

 understood, — the principle is in every instance the same ; the differ- 

 ence being merely relative and not absolute. 



" Or, if we choose to vary the simile, we may compare the whole 

 system to a cord, upon which beads, of innumerable sizes, patterns, 

 and colours, have been densely strung. Now, if there were no such 

 things as natural divisions in the organic world, these beads (which 

 represent the separate species) might have been disposed of anyhow, 



their positions with respect to each other would under those circuin- 



