DUBLIN NATUEAL HISTORT SOCIETY. 1 79 



turn is closely similar to Hymenophyllum flexuomm of New Zealand, but 

 differs in the margin of the indusium being fimbriate. Other cases could 

 be adduced whore the distinctions shown in botanical works are not 

 more strongly marked than those that separate Wilsoni from Tunbrid- 

 gense. In submitting to the meeting the beautiful specimens of Adi- 

 antum asarifolium from Bourbon, it must necessarily be seen how slight, 

 in accordance with the present views, are its specific differences if om 

 the Adiantum reniforme of Madeira. The venations in both plants are 

 the same, the character and position of the son precisely similar, the 

 Bourbon plant only differing in presenting a more robust habit of growth, 

 and in the character of the deep sinus in the frond. The Bourbon plant 

 may be considered the type, the Madeira and those of the Canary Isles, 

 the sub- type, of the one species. Yet in the peculiar features of each 

 plant, which are constant throughout, there are fully sufficient grounds 

 in the aspect, habit, and locality of the Bourbon plant to justify specific 

 distinction. I am, however, in correspondence with friends, both in 

 Bourbon and New Zealand, who will probably send me this plant, and 

 those of Trichomanes £ind Hymenophyllum, packed in a manner which 

 I have found very successful in keeping them in a living and fresh state 

 for many mouths without injury. 



I had no intention in my former statement, nor in this, to dispute the 

 views of Mr. Bentham, as I am perfectly aware of the difficulties that 

 still beset the classification of ferns. However, in his inroads on British 

 Botany he has raised a host of labour which years cannot accomplish, and 

 which all his experience of Continental herborization will not be equal to. 

 I am far from disagreeing, however, in thejudicious reduction of the too 

 numerously recorded species, but the enlarged views which shrivel 

 specific distinctions into nonentity will involve no useful end, and will 

 certainly render the study less intelligible and less pleasing. I do not 

 pretend, neither do I venture, nor do I desire, to contend with the great 

 botanists of the day ; but, having been well-grounded by the admirable 

 practical botanical demonstrations of my esteemed friend, Dr. Mackay, 

 the father of Irish Botany of that period, and with the recollection of 

 the field labours and of the pleasing botanical companionships of those 

 days, I hope I may, without presumption, venture an opinion. 



Pkofessob KiNAHAN stated that on the last eyening, when the subject 

 was before the Society, the length of the discussion which then took place 

 had deterred him from making as full a statement as he would have wished 

 of his views, though he could hardly call them his, as they were those held 

 by more than eight-tenths of the field practical botanists both in the 

 British Isles and on the Continent — in fact, he might say all over the 

 world. The remarks he had made had been so misquoted, or misunder- 

 stood, that he felt it due both to himself and to the author of the paper 

 on the Hymenophyllum to enter more fully into some of the arguments 

 then brought forward. It had been stated, or at least hinted, that the 

 advocates of the specific difference of these forms had only assertion to 



2c 



