I3 DESCRIPTIVE BOTANY. PART I. 



the uses which a systematic arrangement of natural 

 bodies is intended to serve. This subject has been 

 thoroughly and sufficiently discussed by Mr. Swainson, 

 in our sixty-sixth volume. We may just remark, that 

 the number of species already named and classified in . 

 works of botany, amounts to about 60,000 ; and this 

 fact alone must satisfy us, how necessary it is that 

 botanists should possess those means of intercommuni- 

 cation, which a systematic classification alone can afford 

 whenever they wish to announce the discovery of a 

 new species, or to refer, with certainty, to one which has 

 been previously noticed. But, if we have the higher 

 object in view, of searching after the laws and princi- 

 ples which regulate the structure and fix the properties 

 of plants, then it is a necessary and immediate conse- 

 quence of every discovery of this kind, that we thereby 

 obtain a nearer conception of those affinities by which 

 plants approach, and of those differences by which they 

 recede from each other ; and this, in fact, amounts to 

 a closer insight into that hitherto undiscovered system, or 

 plan, upon which we must feel satisfied that the Author 

 of nature has proceeded in creating all natural objects. 



(131.) Natural Groups. We have already (art. 

 33.) mentioned the leading characteristics of the three 

 primary groups, or classes, into which plants seem 

 to be naturally divisible. Each of these, again, admits 

 of subdivision into minor groups, which severally con- 

 tain such species as are more nearly related to each 

 other than to those of other groups. By further sub- 

 divisions of this kind, a subordination of groups, of 

 smaller and smaller dimensions, is obtained, until we 

 arrive at those groups which do not readily admit of 

 further subdivision, and which are termed "genera." 

 It must, however, be obvious that this method, of 

 analysis, is not the actual process in which the primary 

 groups were originally established. This was effected 

 by a synthetical mode of procedure by comparing 

 separate individuals, and by selecting those which most 

 nearly resembled each other ; and thence establishing, 



