DARWINISM. 33 



in Darwin's time was supposed to be useless is now 

 accounted for and shown to have a meaning, to 

 be either directly useful or correlated with that 

 which is useful : 



" Almost every detail," says Mr. Wallace, speaking specially 

 of plants, " is found to have a purpose and a use. The shape, 

 the size, and the colour of the petals, even the streaks and 

 spots with which they are adorned, the position in which 

 they stand, the movements of the stamens and pistils at 

 various times, especially at the period of and just after 

 fertilization, have been proved to be strictly adaptive in so 

 many cases that botanists now believe that all the external 

 characters of flowers are, or have been, of use to the species." 



The main interest, however, of Mr. Wallace's 

 volume gathers round the last two chapters, the 

 former of which contains an elaborate criticism of 

 some modern theories of evolution opposed to 

 Darwinism, and a clear statement of the recent 

 speculations of Professor Weismann, while the last 

 chapter deals with the question at issue between 

 himself and Darwin. 



Of views opposed to Darwinism four typical 

 theories are discussed, all of them tending, in 

 different ways, to minimize the action of natural 

 selection, while three out of the four stand or fall 

 with the possibility of inheriting acquired characters. 

 The first and most important of these is the view 

 of Herbert Spencer, which, though it runs through 

 his works, has lately received special attention, 

 because an article written by him for a popular 

 review on the " Factors of Organic Evolution " was 



D 



