III. 



THE PLANT INDIVIDUAL IN THE LIGHT OF 

 EVOLUTION/ 



THE PHILOSOPHY OF BUD -VARIATION, AND ITS 

 BEARING UPON WEISMANNISM. 



Whilst the animal and vegetable kingdoms originate 

 at a common point and are not clearly distinguishable 

 in a number of the lower groups of organic beings, they 

 nevertheless diverge rapidly, and finally become very 

 unlike. I believe that we shall find that this diver- 

 gence into two co-ordinate branches of organic nature 

 is brought about by the operation of at least two fun- 

 damentally distinct laws. There is a most unfortunate 

 tendency, at the present time, to attempt to account for 

 all phenomena of evolution upon some single hypothesis 

 which the observer may think to be operative in the 

 particular group of animals or plants which he may be 

 studying. For myself, I cannot believe that all forms 

 of life are the results of any one law. It is probable 

 that all recent explanations of evolution contain more 

 or less truth, and that one of them may have been the 

 cause of certain developments, whilst others have been 

 equally fundamentally important in other groups of 



'Address before the Biological Society of Washington, January 12, 1895. 

 Printed in Science, new series, 1. 281 (March 15, 1895). 



6 SUR, (81) 



