282 



THEOKIES AS TO THE NATUEE OF SPECIES. [Ch. XXXV. 



mi 



N'atural Selection, but also bj showing that, if we assume 

 this principle, much light is thrown on many very distinct 

 and otherwise unconnected classes of phenomena, both in the 

 present condition and past history of the organic world. 

 Hooker on variation and selection and the formation of species 



me 



same 



in the vegetable world. 



doctrine of the ' immutability of species ' was accelerated in 



year (1859), of Dr. 

 Hooker's essay on the Flora of Australia. In several of his 

 previous writings this eminent botanist had said all that could 

 be said in support of the ' constancy of the specific character in 

 the vegetable world.' He had been freely discussing for fifteen 

 years with Mr. Darwin, all the facts and arguments which 

 they could bring to bear on this question, but he stated in 

 his Introduction, that until the views of his friend and those 

 of Mr. Wallace in favour of Natural Selection had been made 

 known, he scarcely felt himself at liberty frankly to declare 

 how far, as a botanist, he was prepared to go in the same 



He had been occupied for more than twenty 

 years in the study of plants of various parts of the world, 

 arctic, temperate, and tropical, insular and continental. He 

 had personally explored the floras of several of these 

 had described and classified thousands of species, and was 

 well known to unite caution with boldness in his philoso- 

 phical speculations. From his new essay the e-eneral public 



direction. 



regions 



most 



botanists are agreed amongst themselves as to the limits of 



mere matter 



of opinion^ even amongst those who believe that species have 

 remained unchanged since their creation^ and Avill remain 



mntable 



Hooker 



study the 



same 



more and more difficult 



characters ; also that in the flora of every country there are 

 some groups of species which are apparently unvarying. 



much 



may 







