44 The Scottish Naturalist. 



So much for the more recent writers. Let us see what the 

 older authors say. Of these, the earliest I can cite is Newman, 

 who, in the ' Phytologist ' for June 1853, describes, for the first 

 time, P. flexile ; and in his work on ' British Ferns/ third edition 

 (1854), describes and figures alpestre and flexile, and considers 

 them to be quite distinct. 



In the descriptions, which are rather too lengthy to reproduce 

 here, stress is laid on many of the characters afterwards given in 

 " Babington." Moore's larger works I unfortunately cannot cite ; 

 but in the abridgment of the ' Popular History of British Ferns,' 

 published in i860, he considers flexile as a "very distinct and 

 remarkable variety" of alpestre, differing "in its lax spreading 

 habit, narrow fronds, short deflexed pinnae, and fewer pinnules." 

 He further remarks that the plant, as seen in cultivation, pro- 

 duces stalkless, or almost stalkless, fronds, which often bear their 

 sori abundantly at the base, but scarcely if at all upwards. These 

 latter characters, however, disappear in some instances in wild 

 and cultivated specimens. 



Finally, I may notice that Mr H. C. Watson, in the last edition 

 of the London Catalogue, places flexile as var. b. of alpestre. 



Thus ail modern authorities except Professor Babington are 

 agreed in reducing flexile to the rank of a mere variety of alpes- 

 tre, and even Babington is not so confident as he once was in 

 upholding the specific rank of flexile. 



Let us now consider — 



1st, What are the characters by which Hexile is distinguished 

 from alpestre. 



2d, What value is to be placed on these characters. 



First, then, the distinctive characters of flexile. Taking the 

 points emphasised by Babington, we will find that he lays stress 

 on the shape of the pinnae, these being (he says) narrow lanceo- 

 late with a broad base and contiguous in alpestre, and ovate 

 lanceolate distant in flexile. I find, however, in my specimens, 

 that the pinnae in both forms are broadest at their base, and that 

 in flexile they cannot be termed distant. In the next place, 

 that (according to Babington) alpestre has pinnules widest at the 

 base, acute, pinnatifid, with serrate lobes and branched vein- 

 lets ; and flexile has pinnules narrow at their base, bluntish 

 serrate, and with unbranched veinlets. Here, I think, we have 

 one distinctive character which is constant — namely, the narrow 

 base of the pinnules in flexile. As for the other characters, I do 

 not find that they serve in all cases to distinguish alpestre from 

 flexile, as some forms of alpestre have pinnules as blunt as in 



