BRITISH FERNS AND THEIR WILD SPORTS. 



83 



numbers which have been discovered and are still being discovered, the 

 immense area of ferny ground which is still unexplored and presumably as 

 prolific, and the great range of variation they present, it would be indeed 

 a strange thing if, in the a?ons of time which are demanded for the great 

 scheme of Evolution, none of these should ever have had sufficient self- 

 assertive power to spread far and wide and become a species proper. 



A species is but a constant variety of a genus, and if its form be 

 permanently changed who can draw a line between it and its congeneric 

 fellows, and deny it a specific title ? In the exotic asplenia, to take a 

 familiar instance, we have numerous recognised distinct species which differ 

 far less between each other than do many of our British sports. These 

 sudden "sports," as we know, are not confined to ferns ; they occur in all 

 branches of organic life. Among animals, marked " sports " in cattle have 

 proved to be so prepotent as to breed true with the normal type, and it is 

 very probable that apart from outward structure, there may be what may 

 be termed constitutional sports, involving greater hardiness or tenderness, 

 or even, in animals and insects, different proclivities and habits, so that 

 the sudden appearance of new pests and diseases, or the sudden pre- 

 dominance of old ones, may well be due to ' 4 sports" of this kind in the 

 organisms which constitute them. Without, however, entering farther 

 into these somewhat abstruse regions of the subject, I venture to think 

 that we may congratulate ourselves that the days when such " sports " 

 were regarded as mere natural freaks, unworthy entirely of scientific 

 notice, are passing away, and that it is now appreciated that they 

 present a valuable and inexhaustible field of profitable research. 



Note. — It was impossible to reproduce as illustrations to this lecture 

 all Mr. Druery's slides. — Ed. 



