260 
ASPLENIACEiE. 
represented at page 257, figure c. This specimen was I believe 
gathered by Dr. Allmann, from whom I have received an inte^ 
resting note on the subject. “ There may be some doubt,” 
writes Dr. Allmann, as to the necessity of considering it sepa- 
rately from the common form of Adiantum-nigrum, for though 
the extreme forms are so remarkably distinct as to strike the 
most casual observer, yet these extremes are connected by such 
numerous gradations, by which they run into each other, that I 
believe it to be impossible to say where the more common variety 
terminates and the rarer one commences : the great elegance, 
however, of ivell-marked specimens of the rarer variety, and the 
facility with which they may be distinguished from the common 
form, seems to render a separate notice of the fern desirable.” 
Mr. Mackay, when recently in London, informed me that under 
cultivation he had found this plant return to the usual form. I 
entertain no doubt that the plant thus noticed by Ray, Dillenius, 
Smith and Mackay, and also by Miss Carpenter and Dr. All- 
mann, and of which a specimen is now before me, is identical 
with the Asplenium acutum of Bory, Sprengel, Willdenow and 
Sadler. 
