CHAPTER VIII 

 MORE ABOUT SPECIES 



I WROTE in the last chapter of the recognition of 

 that degree of " likeness " or kinship in animals and 

 plants which we point to by the word " species," and 

 of the grouping of several similar species to form a 

 " genus," and of several genera to form a family, of families 

 to form orders, and of orders to form classes — and of the 

 giving of names to all these groups. Whilst the making 

 of this or that lot of species into a distinct genus, and 

 giving it a new name is a mere matter of convenience 

 for the indication of more or less important agreements 

 and divergences, and is to a large extent arbitrary or an 

 expression of opinion — it has always been recognized 

 among naturalists that the group called "a species" is 

 not a mere convention, but has a real natural limitation. 

 It is true that the actual things which we see in study- 

 ing natural history are so many units or individuals. 

 But the possibility of arranging these by pattern, colour 

 and shape into ultimate companies of which all the 

 units are alike and differ from all the units of another 

 company, has been regarded as a natural fact of 

 primary importance and not a mere convention or 

 convenience. The conception of the "naturalness" of 

 a species depends really upon a further qualification of 

 great importance as to what we naturalists understand 

 by it. 



We find by rearing plants from seed and by causing 



