BRISTLE FERN. 
317 
Ogilby, of Dublin, whose name I hav^e before mentioned as a 
kind contributor of specimens, seems quite to coincide in Mr. 
Moore’s view of the case. 
In accordance with the views previously urged, when describ- 
ing Cystopteris fragilis and Lastrcea multiflora^ I have en- 
deavoured to compare the most mature and perfect fronds from 
each locality, and the result appears to be 1st — that the speci- 
mens from Glouin Caragh are far more mature and fruitful than 
those from Killarney ; it is a rare thing to obtain specimens from 
the latter station in a thoroughly mature state ; I think I may 
say that not one frond in fifty exhibits involucres, and not one 
in many hundreds attains the perfect development and fruitful- 
ness displayed by the Glouin Caragh plant ; but 2ndly — I find 
that the most mature of the Killarney specimens most recede 
from the Glouin Caragh specimens, a circumstance rather op- 
posed to the supposition that the two are identical, since in 
general we find ferns developing their specific dififerences more 
strikingly as they approach perfection. 3rdly — The length of 
receptacle is another test of perfection : the Killarney plant, 
grown at Killarney, has a receptacle of very different length ; 
in the most perfect specimens it is at least four times as long as 
the involucre, in the least perfect it scarcely protrudes beyond 
the involucre, and under cultivation it is seldom to be seen at 
all, thus evidently proclaiming that its length in some measure 
depends on health, maturity, and a congenial situation. Will- 
denow, in the passage cited, describes the receptacle as four 
times the length of the involucre ; and I cannot assert either 
that its frequent departure from this character at Killarney 
proves anything more than that such departure is a testimony 
of imperfection, or its attaining this character at Glouin Caragh 
is to be attributed to any other causes than congenial situation. 
The form of frond may be capable, as Mr. Moore asserts, of 
great elongation, but there is no evidence that the relative length 
of the pinnae is also altered : it appears to be a fundamental 
character of a deltoid frond that the lowest pair of pinnae shall 
be longer than the second pair, the second longer than the third, 
and so on ; and, as far as I am aware, this character is Constantin 
cultivation ; at least I can safely assert that it is so in Asplenium 
