161 



On the Fibro-vascular Bundles in Ferns and their 

 Value in Determining Generic Affinities. 



By J. W. Morris, F.L.S. 



Communicated by T. Curties. 

 {Read October 27th, 1882.) 



PLATES IV. and V. 



Everyone, it may be assumed, Las, at some time or other, made a 

 section, however rough, of the stipes or frond stalk of the common 

 Bracken (Pteris aquilina), and observed the diagram of the Oak 

 tree which the fibro-vascular bundles with their scalariform ducts, 

 thus seen in section, are thought to represent. 



A wider acquaintance with sections of this character discloses 

 some highly interesting] affinities, and suggests a law of correspon- 

 dence and development which, if once accurately laid down, must, it 

 is thought, be of value in the determination of genera. 



It is by no means suggested that genera can be determined by 

 this evidence alone. The existing characteristics, hitherto ex- 

 clusively relied upon, are indispensable and primary, but it is 

 believed that the due consideration of this feature of growth would 

 tend to correct or remove many existing anomalies which at present 

 sorely afflict and confuse the student of Fern classification. 



No one who has attempted to master the existing arrangements 

 and apply them practically to the identification of species, or even 

 genera, is insensible of the anomalies which exist. 



The present classification — or classifications rather — however 

 scientific in their broader features, are little better than capricious 

 in a multitude of individual instances. 



"We should be in despair in our Phanerogamic Botany if one 

 authority placed the Tulip tree amongst Tulips, and another trans- 

 ferred the Salisbuvia adiantoides from the Yews to the Adiantums— • 

 but it is pretty nearly as bad as this in Fern-land. 



