102 VITALISM AND SCHOLASTICISM 



different from one another, so utterly uncon- 

 vertible into one another, are all the descen- 

 dants of a single cell and have been derived 

 from it by processes similar to those described 

 in the earlier part of the present chapter. 

 Perhaps one may pause for a moment here to 

 consider the bearing of these facts upon the 

 question with which this book is concerned. The 

 living body is often compared to a machine and 

 is said by some to be nothing but a machine 

 and explicable, did we know all the facts, on 

 the same laws and principles as those whereby 

 a machine is explained. Those who hold such 

 views have, at least so it seems to the present 

 writer, to^encounter enormous , even insuper- 

 able Hiffip.iilt.ip.sj, when they arrive at this sub- 

 ject of development; for let us grant that the 

 cell the single cell is a machine for the pur- 

 poses of argument. Let us even suppose that 

 such a machine should be capable of producing, 

 of its own mere motion, other machines like 

 unto itself. That is a sufficiently large assump- 

 tion, since no machine has ever yet been made 

 or thought of which does anything even faintly 

 foreshadowing what is here imagined. Nor 

 has any chemical compound the power of re- 

 duplicating itself, by means of its own inherent 

 forces. Suppose even that these things were 

 believable they are nothing to what happens in 



