250 NATUBAL HISTORY SOCIETY OF DUBLIN. 



Dr. Moore said, he had under cultivation some of the varieties enu- 

 merated by Mr. Harte, and they had held good. Mr. Harte's remark 

 as to their relation to particular geological formations was interesting. 

 This was a point to which too little attention had been paid ; for it 

 would he interesting to ascertain whether certain varieties prevailed in 

 certain geological formations, or not. Mr. Harte had stated that he 

 found this to be the case with respect to some of the species. Some of 

 the species of plants commenced to grow in Donegal, and reached west- 

 ward, while the district in which others were found seemed to end in 

 Donegal, so that it was a transition county for some of the rarest 

 species. 



The President wished to ask Mr. Harte "the question, does the 

 Osmunda shun limestone? He had found it common in the valley of 

 Kenmare, but it seemed to shun the limestone there. The high 

 ground of the district was slate or sandstone, and the lower ground 

 limestone ; consequently there was a narrow fringe between the loca- 

 lity it avoided and the upper, where it grew to four or five feet in 

 height. 



Mr. Andrews observed that geological formation had doubtless 

 much influence upon local distribution of plants. He had, however, 

 seen fine specimens of Osmunda regalis, attaining a height of eleven feet, 

 growing around the margins of the islands, which were of limestone 

 formation, opposite Muckross, Killarney. With regard to the form 

 of Cystopteris that had been alluded to, a variety of forms agreeing 

 with several that had been described as distinct were to be met with at 

 different elevations on the range of the Benbulben Mountain, in Sligo. 

 Like C. alpina and C. dentata, they were but mere departures from the 

 form that Cystopteris fragilis generally presented. He had collected a re- 

 markable series of those varieties ; and it was singular that in cultivation 

 they still retained those characters of growth similar to the same that 

 occurred among such varied forms of our Saxifrages. There are plants 

 that affect peculiar formations, yet at the same time were found to be 

 distributed in soils that differed. Adiantum capillus- Veneris, that grows 

 bo abundantly in the limestone districts of Burren, in the county of 

 Clare, and in the Arran Islands, Galway Bay, has been found growing 

 on clay-slate in the county of Leitrim, and on Old Eed Sandstone, Cahir- 

 conree Mountain, Kerry. The plants of Burren seemed peculiar to that 

 district, and were identical with the Adiantum Africanum described by 

 Robert Brown as found in the Island of Goletta, in the Mediterranean, 

 and on the African coast. They differed materially in growth from 

 those of the South of Europe, and the specimens from Cornwall. Many 

 of the Cryptogamic plants, as the mosses and lichens, were solely con- 

 fined to peculiar formations. Mr. Harte's views were of interest as de- 

 scribing the bounds of distribution of the Ferns he had enumerated, yet 

 plants that would appear usually associated with particular geological 

 formations had in instances been met with distributed in localities of 

 other formations. 



