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CHAPTER XXIV. 



BOTANICAL WORKS (1862-86). 



Darwin's botanical works are referred to separately, 

 and receive more systematic treatment than the others, 

 in the great " Life and Letters." They form, together 

 with the botanical letters, the subject of the seventh 

 to the twelfth chapters in the last volume. It will 

 therefore be unnecessary to treat them in any detail, 

 although they form some of the most important and 

 interesting of all his biological investigations. 



Fertilisation of flowers. — " The Fertilisation of 

 Orchids " was the first published of the botanical works' 

 appearing in 1862, followed by a second and greatly 

 altered edition in 1877. The object of the work "is 

 to show that the contrivances by which orchids are 

 fertihsed are as varied and almost as perfect as any of 

 the most beautiful adaptations in the animal king- 

 dom ; and secondly, to show that these contri- 

 vances have for their main object the fertilisation of 

 the flowers with pollen brought by insects from a dis- 

 tant plant." Even in 1837 Darwin had written in his 

 note-book, "Do not plants which have malp and 

 female organs together {i.e. in the same flower] yet 

 receive influence from other plants ? Does not Lyell 

 give some argument about varieties being difficult to 



