ANALOGY AND AFFINITy ILLUSTRATED. 231 



have required an almost infinite degree of design before 

 they could have been made exactly to harmonise with 

 each other. When, therefore, two such parallel series 

 can be shown, in nature, to have each their general 

 change of form gradual, or, in other words, their rela- 

 tions of affinity uninterrupted by any thing known — 

 when, moreover, the corresponding points in these two 

 series agree in some one or two remarkable circum- 

 stances, there is every probability of our arrangement 

 being correct. It is quite inconceivable that the utmost 

 human ingenuity could make these two kinds of re- 

 lation tally with each other, had they not been so 

 designed in the creation. Relations of analogy consist 

 in a correspondence between certain insulated parts, or 

 properties, of the organisation of two animals which 

 differ in their general structure. These relations, how- 

 ever, seem to have been confounded, by Lamarck, and, 

 indeed, all zoologists, with those upon which orders, 

 sections, families, and other subdivisions, immediately 

 depend.* 



(285.) To illustrate by an example the above de- 

 finition, we will take two groups of birds, whose 

 relations are unquestionable. The first shall be the 

 primary orders of the class ; the second, the primary 

 tribes of the perching order. By placing these in " pa- 

 rallel series," it will be found that the corresponding 

 points of each agree in some one or two remarkable pe- 

 cuharities of structure or of habits. 



Orders of Birds. Tribes of Perchers. 



1. TvpicAL Group. Insessores. . . Conirostres. 



^ 2. Sub-typical Gbodp. Raptores . . . Dentirostres. 



fNalatores . . . Fissirostres. 



3. Aberrant Group. -! Grallatores . . Tenuirostres. 



[_ Rasores . . . Scansores. 



Here we have two series of natural groups arranged 

 parallel to each other, but of different ranks. The first 



• Hor. EnL p. 363. 

 Q 4 



