2 PREFACE. 



to those for whom it was from time to time conceived, 

 — for horticulturists first, for evolutionists next. The 

 essays are of unequal merit, and there are necessarily 

 repetitions in them; but I conceive that they are the 

 more valuable for having been written at diffei*ent 

 times and for different occasions, for they thereby pre- 

 sent the subjects in more diverse aspects. The audi- 

 ences to whom the greater number of the essays have 

 been addressed have been composed of persons who 

 observe widely of facts, but who are unused to mak- 

 ing broad inductions from 'them. It is only in the 

 first two essays that I have ventured to state any 

 general convictions respecting the bolder problems of 

 organic evolution, but I count these of much less 

 merit than the statements of many plain and simple 

 facts of observation and experiment which are made 

 in the humbler essays. If the author has been fortu- 

 nate enough to make any contribution to positive sci- 

 ence in these pages, it is probably that associated 

 with the vexed question of bud -variation, which is 

 chiefly presented in the third essay; but even this is 

 novel only in its treatment. The underlying motive 

 of the collection is the emphasis which is placed upon 

 unlikenesses, and of their survival because they are 

 unlike. The author also denies the common assump- 

 tion that organic mutter was originally endowed with 

 the power of reproducing all its corporeal attributes, 

 or that, in the constitution of things, like produces 

 like. He conceives, as explained on pages 20 to 24, 



