1900] BRIEFER ARTICLES 413 
no such thing as fertile hybrids between fern species. If we grant the 
specific distinctness of acudeatum and angulare, the converse has now 
. been proven. The fertility of certain varietal crosses seems well 
established, and it may be regarded as by no means improbable that, 
with the use of careful methods, the same may be unquestionably 
proven in the case of a good number of specific hybrids. 
Regarding the relationship of A. edenoides to its supposed parents, 
Professor Eaton remarked ™ that “while it differs from the first [Camp- 
tosorus] by its dark and shining stalk and rachis, in its free veins, and 
by its pinnatifid or sub-pinnate frond, it resembles it strongly in the 
prolonged and slender apex, and especially in the proliferous buds; 
and in the very respects in which it differs from this it resembles the 
other.” These very features of resemblance appealed to Berkeley with 
sufficient force to induce him to advance the hybridity proposition ; 
but Professor Underwood apparently attaches little importance to 
them, considering the plant closely allied to Asplentum pinnatifidum, in 
which he is supported by Professor Murrill.” The fern seems to 
me to exhibit conspicuously certain characters of both its supposed 
parents, not the least important of which is the more or less frequent 
anastomosing of the veinlets. This fact is easily noticeable in a good 
share of the specimens, as noted by Professor Murrill in commenting 
upon Professor Eaton’s statement to the effect “ veins are everywhere 
free,” a character distinguishing all true Asplenia. Its propagation 
_ through proliferation at the apex, questioned by Professor Murrill, was 
vouched for’ in cultivated plants as early as 1878 by Mr. D oe yo 
and lately Mr. William Palmer has collected fronds in Maryland in which 
the pinnae bear at their tips minute but well-formed young plants. 
A good proportion of the plants collected this summer at Havana by 
Mr. Pollard and myself bear young plants at the apex of the fronds, 
: but I have yet to notice any of fair size and large enough to thrive if 
_ Stparated from the parent plant. I am inclined to believe that these 
Young plants never come to an independent existence. If they are 
indeed abortive, the fact may be taken as tending to substantiate the 
Claim for its intermediate position. 
Another feature in the morphology of the plant oleae a i. : 
Cially Significant is its marked asymmetry. Even in examining aa 
great growth at Havana it is extremely difficult to discover what wou 
“Ferns of N. Am. 1: 26. 
_'SFern Bull. 5:1. 1897. 16 Bull. Torr. Bot. Club 6 :200. 1878. 
