24 FERNS IN- THEIR HOMES AND OURS. 



whether the several gradations of allied forms are 

 descendants of primitive specific creations, or are, 

 according to the Darwinian theory of the ' origin 

 of species,' only derivations from primordial crea- 

 tions endowed with a protean principle which 

 becomes manifest during the lapse of ages, and 

 controlled by the different climatic and local influ- 

 ences under which the progeny of the original 

 have become established, and which now form the 

 flora of the earth." 



The definition given of a species, " a collection 

 of individuals identical one with another, and 

 capable of reproducing their like from age to age," 

 is quite in contrast with what has just been quoted. 

 Therefore, when we find that doctors disagree," 

 it does not require much courage to say of a 

 species that it is to be treated as genera, orders, 

 and classes have long been, and is what we choose 

 to make it ; and also that the best way to decide 

 upon the merits of any one case is to accept the 

 judgment of the most eminent authors who may 

 have given special study to its forms as to what 

 the limits of the species shall be. Let us there- 

 fore, for convenience' sake, consider that a species 

 is a collection' of individuals varying but slightly 

 one from another, and capable of producing their 

 like ; and that the limits of the species shall be 

 according to the best judgment of those having 

 the advantage of the most specimens for compari- 



