456 COSMIC PHILOSOPHY. [ft. It 



■which do not fly; the caecum, or blind intestine, and the 

 terminal vertebra?, in man; and the incisor teeth in calves 

 and other ruminants, which never cut through the gum. N< 

 explanation can be given of such phenomena, save on the 

 theory of inheritance; for the pompous statement, which wo 

 sometimes hear, that such organs have been created " for the 

 sake of symmetry, and in order to complete the scheme of 

 nature," is no explanation at all. As Mr. Darwin pertinently 

 asks, "Would it be thought sufficient to say that because 

 planets revolve in elliptic courses round the sun, satellites 

 follow the same course round their planets, for the sake of 

 symmetry, and to complete the scheme of nature ? " Moreover, 

 if we were to rest content with this arbitrary assumption, we 

 must needs confess that the symmetry of nature has been but 

 imperfectly wrought out; for the rudimentary organs which, 

 on this hypothesis, ought always to be present, are often 

 entirely wanting. 



In this connection the history of the long exploded hypo- 

 thesis of Preformation becomes very instructive. The argu- 

 ment is ably presented by Mr. Lewes, in a series of essays on 

 Darwinism, which are still buried among the back numbers 

 of the " Fortnightly Beview," but which, it is to be hoped, 

 will presently be reprinted in some more generally accessible 

 form. Mr. Lewes calls attention to the fact that those who 

 still profess to find it incredible that a complex organism 

 should have been developed through long ages and through 

 countless intermediate forms from a unicellular creature like 

 the amoeba, nevertheless find nothing incredible in the de- 

 monstrated fact that complex organisms are developed in a few 

 weeks or months from minute homogeneous germ-cells. Now 

 it is instructive to note that to the physiologists of a century 

 ago, the latter process of development seemed quite as in- 

 credible as the former. The process by which a structureless 

 germ, assimilating nutriment from the blood of the parent 

 organism, becomes gradually differentiated into such an 



