FERN CONFERENCE. 



505 



representing an independent line intermediate between the 

 Eusporangiate Ferns and the Lycopods. 



But while we may thus speculate as to the evolutionary 

 relations of these several forms, it will be well to hold firmly to 

 the main point which has served as the basis for this discussion, 

 viz. that on the ground of detailed comparison the homosporous 

 FilicinecB form a natural series extending between two extremes. 

 At the one end of the series may be placed those in which all the 

 parts are relatively bulky in origin, and show irregularity of 

 meristematic segmentation — these are the Eusporawjiatcc ; at 

 the other end of the series are those in which all the parts are 

 relatively delicate in construction, and the meristematic segmen- 

 tation is definite and regular — these are the Filmy Ferns. In 

 this series we probably see the results on the one hand of adapta- 

 tion to relatively dry conditions, on the other to a comparatively 

 humid habitat ; and, whichever end of the series is ultimately 

 proved to have been the primitive one, the fact that the series 

 exists is, in my opinion, beyond the possibility of doubt. 



HYBRID FERNS AND CROSSED VARIETIES. 



By Mr. E. J. Lowe, F.R.S. 



A papeii embracing all that is of interest in so important a 

 subject as hybrid species and crossed varieties would occupy 

 more time than could be devoted to it this afternoon. An outline 

 is all that can be attempted. 



It is comparatively a new branch of inquiry, and fresh facts 

 are constantly cropping up. 



Although the crossing of Ferns has only been recently 

 acknowledged, nevertheless my own investigations, experiments, 

 and, may I add, successes commenced many years ago, dating 

 even to the middle of the century. It has therefore been thought 

 that a brief history of my own work may not be unacceptable. 



In the first place, let me explain that a hybrid Fern is the 

 offspring of two so-called species — as example, between Asplcnium 

 marinum and Asplcniiun lanccolatum, whilst the offspring of 

 two varieties of the same species is called a cross. 



H 



