DrBLIir WATUBAL HISTOBT 80CIETT. 175 



sufficiently convey ; and at the same time I feel called on to make some 

 comments on the presumed discussion on that statement which appeared 

 in " Saunders' News-Letter" of the 16th of last month, and which was 

 not published through the authorized channel of the Society, nor did it 

 convey the points strictly in accordance with the verbal expressions and 

 views given at the meeting. In alluding to the localities of the species 

 H. Tunhridgense and Wihoni, I merely at the time gave the characters 

 of the extreme habitats of each, showing that the former required a more 

 shaded and even temperature for its perfect growth and development than 

 Wilsoni, and that in the alpine and exposed positions favourable to the 

 growth of Wilsoni the species Tunbridgense was not observed; that on the 

 confines of such habitats both Wilsoni and Tunbridgense may be found in 

 the same immediate localities together, and each presenting its peculiar 

 form of frond and distinctness of involucre. Mr. Wilson has observed to me 

 " that the two species are usually found apart, and that H. Ihnhridgeme 

 is confined to lower regions than the other species, as must be obvious 

 enough to those who have taken any pains to study them in a wild and 

 growing state." Dr. E. Perceval Wright, F. L. S., made the first remarks 

 in this important discussion, to the effect that he perfectly understood 

 from Mr. Andrews's statement that it went to prove the identity of the two 

 forms, and that the question of species was one not to be settled by as- 

 sertion; that the habits of plants growing in sheltered glens and of those 

 exposed to the influence of the Atlantic in our western islands, in such 

 a limited Flora as that of Ireland, could not, from their altered character 

 of growth, be construed into distinct species ; travel alone could give 

 sufficient experience to decide such questions of diiFerence of habit which 

 growth and climate presented ; that the distribution of those ferns was 

 world-wide, and a form common in Norway could not be considered as 

 a southern type. He further remarked that if, as Mr. Andrews stated, 

 difference of habitat could never alter the ii-uctification of ferns, and 

 that, therefore, in Dr. Wright's opinion, this constancy of fructification, 

 if proven, would at once establish species, and set the question of species 

 for ever at rest. Dr. Wright did not object to local varieties being dis- 

 tinguished by names, as it was of some importance to know of their ex- 

 istence, proving, as they did, how climatal influence seemed to alter 

 forms. Professor Harvey is reported to have stated that he agreed in 

 considering the two forms as one species ; but that botanists having only 

 a knowledge of British botany would at once be led astray in the matter; 

 that fructification was not a constant character in ferns. Sir William 

 Hooker, owing to a great difference on this point, had placed a fern — 

 Ceratopteris, from the tropics — in a separate family from Parkeria from 

 Demerara ; but since intermediate forms had been found, which united 

 those two so different- looking varieties not only into the same genus, but 

 into the same species. Even in the common Hart's-tongue, fructification 

 assumed different positions. These were the leading points that were 

 put forward as the views of Dr. Wright and of Professor Harvey in the 

 unauthorized statement, and, as I have remarked on their incorrectness, 



