88 LAY SERMONS, ESSAYS, AND REVIEWS. [vi. 



animals, though they may differ a good deal from the lobster, are 

 yet either very like it, or are like something that is like it. The 

 cray fish, the rock lobster, and the prawn, and the shrimp, for 

 example, however different, are yet so like lobsters, that a child 

 would group them as of the lobster kind, in contradistinction to 

 snails and slugs ; and these last again would form a kind by them 

 selves, in contradistinction to cows, horses, and sheep, the cattle 

 kind. 



But this spontaneous grouping into &quot; kinds &quot; is the first essay 

 of the human mind at classification, or the calling by a 

 common name of those things that are alike, and the arranging 

 them in such a manner as best to suggest the sum of their 

 likenesses and unlikenesses to other things. 



Those kinds which include no other subdivisions than the 

 sexes, or various breeds, are called, in technical language, 

 species. The English lobster is a species, our cray fish is 

 another, our prawn is another. In other countries, however, 

 there are lobsters, cray fish, and prawns, very like ours, and yet 

 presenting sufficient differences to deserve distinction. Natural 

 ists, therefore, express this resemblance and this diversity by 

 grouping them as distinct species of the same &quot;genus.&quot; But the 

 lobster and the cray fish, though belonging to distinct genera, 

 have many features in common, and hence are grouped together 

 in an assemblage which is called a family. More distant resem 

 blances connect the lobster with the prawn and the crab, 

 which are expressed by putting all these into the same order. 

 Again, more remote, but still very definite, resemblances 

 unite the lobster with the woodlouse, the king crab, the 

 water flea, and the barnacle, and separate them from all 

 other animals ; whence they collectively constitute the larger 

 group, or class, Crustacea. But the Crustacea exhibit many 

 peculiar features in common with insects, spiders, and centipedes, 

 so that these are grouped into the still larger assemblage or 

 &quot; province Articulata; and, finally, the relations which these have 

 to worms and other lower animals, are expressed by combining 

 the whole vast aggregate into the sub-kingdom of Annulosa. 



