222 REMARKS UPON THE 



tacea and the Phocidce among his fish. Now, on comparing 

 a porpoise with a cod, no one could deny that they both 

 were fish according to the assumed definition, yet no natu- 

 ralist would assert the resemblance between them to be one 

 of aflinity. It is evident then, that the word affinity derives 

 its meaning fi*om a belief, acknowledged or tacit, in a natural 

 system, and I do not see how a person who denies the latter, 

 can attach any meaning to the former, as distinguished from 

 analogy. 



From the above definition of affinity, it follows that the 

 degree of affinity is inverse to the rank of the group, in other 

 words, that the members of the lowest group have the high- 

 est or nearest affinity, and vice versa. The nearest of all 

 affinities is that which subsists between species of the same 

 genus, and the most remote is that between animals and 

 vegetables, as members of the next highest group, viz. organ- 

 ized bodies. The affinity between two very distantly allied 

 species, is merely that between the highest separate groups 

 to which they belong. Thus, the affinity between a bat and 

 a goatsucker (to take Mr. Westwood's illustration), is merely 

 that which subsists between mammals and birds, as members 

 of the group Vertebrata, and is seen quite as perfect in the 

 whale and the humming-bird, or any other examples of the 

 two classes. By parity of reasoning, the affinity of a goat- 

 sucker to a dragon-fly is merely that which subsists between 

 the subkingdoms Vertebrata and Annulosa, as members of 

 the natural group Animals, and is, therefore, quite as strongly 

 exhibited in the case of a shark and a butterfly, or an ele- 

 phant and a mite, &c. We thus perceive the distinction 

 between affinity and analogy to consist, not in degree, but in 

 kind, for there is undoubtedly a very strong analogy between 

 a goatsucker and a dragon-fly, though the affinity, as above 

 shown, is very remote. Analogy, in short, is nothing more 

 than an agreement in non-essential characters, or a resem- 

 blance which does not constitute affinity. Hence, analogy 

 is necessarily a very partial resemblance, existing, as Mr. 

 Westwood remarks, in the "numerical minority" of charac- 

 ters, and often confined to one organ alone. Analogy origin- 

 ates, not in the ititentional relation of one species to another 

 at their first creation, but in the other instance of creative 

 design above referred to, viz. the adaptation of organic 

 beings to their destined conditions of existence. To perform 

 any given mechanical action, there is one, and in general, 

 only one, arrangement of mechanical structure which is bet- 

 ter adapted to that end than all others, and hence, when any 

 two beings, whose affinities are remote, are destined to per- 



