1 76 DUBLIN NATTTBA-L HISTOBY BOCIETT. 



are certainly not given in the manner as expressed by Professor Harvey. 

 Upon these points I shall make observations as concise as possible, leav- 

 ing Professor Kinahan to explain more properly his own statements. 



I cannot imagine in what manner Dr. Wright was led to suppose that 

 the characters of aspect and habit, as well as of the peculiarities and forms 

 of the involucres described by me, went to prove identity. In the in- 

 troductory part of my former statement, I, in a very guarded manner, 

 explained the difficulties of demonstrating specific differences, and in 

 general terms mentioned the principles of fructification as of important 

 bearing in distinguishing the characteristics that would mark the ori- 

 ginal or normal form. It was unnecessary to go into detail of those 

 definitions with regard to venation, the direction of the venules, the form 

 and position of the sori, and the character of the indusium, or its non- 

 existence, for they are known to botanists ; but it never could be ima- 

 gined that such alone constitute specific diff'erences; for the general 

 aspects and habits of species may be very different when the venation 

 and the character of the sori are the same. In the present instance the 

 specific distinctions are supported by the aspects and habits of the plants, 

 which locality does not alter ; and in the difierent character of the in- 

 volucres — characters which, as shown in continental works, and in those 

 on exotic ferns, prevail thi'ough all the genera. I do not infer that 

 correct deductions can be established in all such cases ; yet where good 

 apparent distinctions can be shown, it would be better to allow the pri- 

 vilege of their retaining their local names, to which Dr. Wright does 

 not object. 



Limited as the Flora of Ireland may be, yet the botanist well 

 grounded in the practical science of that field may be as competent to 

 understand the merits of a good exotic herbarium as many who employ 

 themselves in describing plants which they have never seen in the grow- 

 ing or in the recent state. I mentioned Aspidium spinulosum, which 

 assumes, according to locality, such a variety of aspects, from its growth 

 in the deep, sheltered glens to the highest mountains, to which were ap- 

 plied the specific terms Foeniscecii, Dilatatum, Recurvum, Dumetorum, 

 &c., yet the characters of fructification were unaltered, and in its stunted 

 state on the mountain top bore copious fructifications. Dr. Wright, how- 

 ever, would imply that the distinction of the form of the involucres in 

 Wilsoni from that of Tunbridgense was altered by the change from a 

 shaded to an exposed position. In the world-wide distribution of those 

 plants it does not appear that the form described by Willdenow, under the 

 name of Tunbridgense, as extending to Norway and Northem Europe, was 

 other than the not then described form Wilsoni. There is no record by 

 Willdenow of the existence oi Hyinenophyllum unilaterale in Europe, and 

 the form now described by continental botanists under that name is pro- 

 bably none other but Wilsoni. Professor Harvey stated that he agreed 

 with Professor Kinahan and Mr. Andrews that those plants in this country 

 were perfectly distinct ; yet that, on the Continent, they were found to 

 run 80 much into each other, that he was of Mr. Bentham's opinion, that 



