WHAT IS A SPECIES'? 935 



or wild, and those which are living in a state of domestication or cultivation. 

 Non-attention to this point is, undoubtedly, responsible for much of the con- 

 fusion which surrounds the word species. Plants which, in the garden, breed 

 true and give the impression of being constant forms and of constituting 

 good species are not found as wild species in a state of nature. This may 

 sometimes be due to their inability to survive in the struggle for existance to 

 which they are exposed in nature, while, in other cases, if growing wild, their 

 characters might undergo fundamental changes owing to their being fertilized 

 by other wild plants. In any case, it must be recognized at the outset that 

 the main object of natural history classification is to enable us to rapidly 

 become acquainted with the principal groups of plants and animals indigenous 

 in various countries, and it must be recognized that the species and its sub- 

 divisions refer to groups of plants as they exist and are found in nature. 

 The following definitions then refer strictly to groups of organisms which 

 exist wild in nature ; similar terms may, of course, be used for analogous 

 groups of cultivated plants or domesticated animals ; but if so, in order to 

 avoid confusion, they should be invariably distinguished by the adjective 

 artificial, thus " artificial species " as opposed to " natural species." 

 Defn. 1. — A species is the smallest group of organisms existing wild in nature 

 which can be readily distinguished from all other groups owing to the fact 

 that the individuals composing it all possess in common certain v;ell- 

 marked characters (= specific characters) by which they can be dis- 

 tinguished from all other organisms. 



The individuals also which compose the species are, ivhen developed 

 normally in a state of nature, always able to transmit their specif c 

 characters unchanged to the majority of their immediate offspring. 

 Defn. 2. — A sub-species is a group essentially similar to a species, but subordinate 

 to it. The characters separating any two individuals belonging to different 

 sub-species not being so great as those which separate individuals belonging 

 to different species. 

 Defn. 3. — A variety is a group of organisms subordinate to a species. The differ- 

 ences between any two varieties of the same species are not constant, i.e., 

 they are not always transmitted unchanged from the parent to the majority 

 of its immediate offspring. 

 Defn. 4. — A eace is a variety of considerable fixity. The characters distinguish- 

 ing the individuals which compose it from those constituting the rest of the 

 species are frequently (e.g., in certain localities, or under certain conditions 

 of existence), but not always, transmitted from the parent to the majority 

 of its immediate offspring. 

 Note 1. — The sub-species corresponds to the French petite espice, and is in all 

 essential characteristics identical with a species. Owing to the enormous 

 number of forms to be dealt with, a Flora, whose object is to help as far as 

 possible those who wish to quickly acquire a knowledge of the principal types 

 of plants indigenous in a very extensive area, must avoid minute detail, and 



