159 



settled ! I am sure all keen students of the Fern World 

 would thank the Editor or someone else of high authority 

 in these matters for a ray of light on this dark subject. 



S. P. Rowlands. 



SPECIES AND VARIETY. 



Dr. F. W. Stansfield. 



In the " Gazette" of December, 1916, continued in this 

 issue, Mr. Rowlands raises the very interesting and perti- 

 nent question, " What is a Species?" In a great 

 measure he answers his own question by realising that 

 11 the division into species is a man-made convention." In 

 this I am persuaded that he is right, for no really satis- 

 factory definition of a species has yet been generally 

 accepted, even if it had been propounded, which is very 

 questionable. The fact that among both zoologists and 

 botanists we have always had " lumpers and splitters" is 

 a practical confession that the word is undefinable. It is 

 agreed that a species means " a sort or kind," but exactly 

 how much difference is required to constitute a species is 

 purely a matter of opinion and individual fancy. The 

 result is that every man who aspires to be "an authority " 

 has his own pet species and genera, varieties and forms. 

 Practically no two writers (unless one is a copyist of the 

 other) are agreed as to the exact number of species among 

 even such a small section of plants as the British ferns. 



Nevertheless, the fact that there is a large measure of 

 agreement with regard to the great majority proves that 

 there is something in the idea of a species. It is not a 

 mere figment of imagination. Mr. Rowlands has quoted 

 a large number of differences of opinion as to British species 

 among botanical writers, so it is unnecesary to labour this 

 point. There is, however, general agreement that e.g. the 



