142 PROGRESS OF SCIENCE. 



tinuous " from nebula to man, from star to soul, from atom 

 to society." He is the high-priest of the evolutionary 

 creed. (Grant Allen's Darwin?) 



To understand the full import of evolution, we must 

 read the crystalline exposition of the system in Spencer's 

 " First Principles " ; but to apprehend its outline we need 

 only recollect its simplest definition. Evolution means a 

 constant and everlasting process of infinite transformation 

 working itself out in regular order, and spontaneously 

 producing new divergences in obedience to, and in harmony 

 with, definite natural laws. In other words, the evolutionists 

 see in evolution " a vast aggregate of original elements per- 

 petually working out their own redistribution in accordance 

 with their own inherent energies." This process applied to 

 the development of plants and animals is very clearly appre- 

 hended too, as soon as we admit, as we must, the " struggle 

 for existence " to which all organised things are subjected by 

 the circumstances which surround them ; for, in that struggle, 

 " variations, however slight, if in any degree profitable to the 

 individual which presents them, will tend to the preservation 

 of that particular individual ; and, being on the average 

 inherited by its offspring, will similarly tend to the increase 

 and multiplication of its species in the world at large." This 

 is the principle of natural selection or survival of the fittest 

 the great principle which Darwin added to the evolutionism 

 of Lamarck and his followers, and which has revolutionised 

 human thought. Of the cause of variation we know little as 

 yet or nothing, unless Weismann has hit upon it in his theory 

 of the persistence of germ-plasm. That would explain the 

 problem ; but the germ-plasm doctrine is far from being as 

 yet an established fact. 



Of all the works of Darwin, besides his "Origin of 

 Species" (1859), the "Fertilisation of Orchids" (1862) and 

 the "Descent of Man" (1871) are the most famous: the 

 first, because it opens the loveliest fairyland of nature ; the 

 second, because it contains all the evidence and arguments 

 which science can furnish of the relationship of man with the 

 rest of the animal kingdom. His u Variation of Animals and 

 Plants under Domestication" (1876) is a storehouse of daily 



