58 EVOLUTION AND DOGMA. 



short with a mere consideration of forms that are, 

 which gives us no insight into their generation, and 

 need not despair of gaining a full insight into 

 this department of nature. The agreement of so 

 many kinds of animals in a certain common plan of 

 structure, which seems to be visible not only in 

 their skeletons, but also in the arrangement of the 

 other parts so that a wonderfully simple typical 

 form, by the shortening and lengthening of some 

 parts, and by the suppression and development of 

 others, might be able to produce an immense va- 

 riety of species gives us a ray of hope, though 

 feeble, that here, perhaps, some results may be ob- 

 tained by the application of the principle of the 

 mechanism of nature, without which, in fact, no 

 science can exist. This analogy of forms in so far 

 as they seem to have been produced in accordance 

 with a common prototype, notwithstanding their 

 great variety strengthens the supposition that they 

 have an actual blood relationship, due to derivation 

 from a common parent ; a supposition which is ar- 

 rived at by observation of the graduated approxima- 

 tion of one class of animals to another, beginning 

 with the one in which the principle of purposiveness 

 seems to be most conspicuous, namely man, and ex-, 

 tending down to polyps, and from these even down 

 to mosses and lichens, and arriving finally at raw 

 matter, the lowest stage of nature observable by us. 

 From this raw matter and its forces, the whole ap- 

 paratus of nature seems to have been derived ac- 

 cording to mechanical laws, such as those which 

 resulted in the production of crystals, yet, this ap- 



