INTRODUCTION. 



caudex of a cormophyllaceous fern : the roots, on the contrary, 

 spreading horizontally, and near the surface of the ground, 

 never terminate in leaves, but possess the power of originating 

 leaves and leaf-branches at any part of their surface except the 

 growing apex ; and not leaves only, but flowers also : such 

 leaf-bearing roots are striking analogues of the rhizome of rhi- 

 zophyllaceous ferns. Could we therefore divide a Pyrus japo- 

 nica into branches and roots, we should have representatives of 

 these divisions of ferns : the branches would be cormophylla- 

 ceous, the roots rhizophyllaceous. 



§mm. 



Concerning genera, I am well aware that I shall be regarded 

 as going too far ; and therefore a few words of explanation 

 seem desirable. In the first place, it must be remarked that 

 the proposed division of annulate ferns into two primary 

 groups, by a character not previously employed, and a division 

 which literally halves such genera as Pol^'podium, Pteris, and 

 many others, necessitates the provision of a new name for one 

 or both of the halves thus dissevered. Were it found that 

 some of the species of Campanula were exogenous and some 

 endogenous in structure, some alteration must be made, either 

 in the classes or the genus. From this cause, the genera 

 Ctenopteris, Eupteris, Lophodium, Grymnocarpium, and Pseu- 

 dathyrium are proposed : three other generic names are intro- 

 duced, because the Linnean specific name had been improperly, 

 as I believe, transferred to the genus ; these are Hemestheum, 

 Phyllitis and Notolepeum. Lastrea montana and Dryopteris 

 Filix-mas are respectively the types of Bory's genus Lastrea and 

 Schott's genus Dryopteris : Lophodium is, I believe, strictly 

 synonymous with the Linnean species Polypodium cristatum ; 

 the name is intended as a Greco-Latin version of the word 



