xxvi Preface to the English Edition. 



we had here a case proving per saltum develop- 

 ment. That this explanation was erroneous is now 

 generally admitted, but I believe that those who 

 suppose that we have here to deal with some quite 

 ordinary phenomenon which requires no explana- 

 tion, now go too far towards the other extreme. The 

 term " larval reproduction " is an expression, but 

 no explanation / we have therefore to attempt to 

 find out the true interpretation, but whether the 

 one which I have given is correct must be judged 

 of by others. 



These four essays lead up to a fifth and con- 

 cluding one " On the Mechanical Conception of 

 Nature." Whilst the results obtained are here 

 summed up, it is attempted to form them into a 

 philosophical conception of Nature and of the 

 Universe. It will be thought by many that this 

 should have been left to professed philosophers, 

 and I readily admit that I made this attempt with 

 some misgiving. Two considerations, however, 

 induced me to express here my own views. The 

 first was that the facts of science are frequently 

 misunderstood, or at any rate not estimated at 

 their true value, by philosophers ; 2 the second 

 consideration was, that even certain naturalists 

 and certainly very many non-naturalists, turn dis- 

 trustfully from the results of science, because 



* I am aware that this certainly cannot be said of philo- 

 sophers like Lotze or Herbert Spencer ; but these are at the 

 same time both naturalists and philosophers. 



