58 
FERNS : BRITISH AND FOREIGN. 
the credit of being the first to employ characters from 
venation upon a large scale is due to Professor Presl, 
who, in 1836, published his celebrated “Tentamen 
Pteridographiae,” where he described one hundred and 
fifteen genera of Polypodiaceas alone, in the characters 
of all of which the venation holds the most prominent 
place. Several years before seeing PresFs “Tenta- 
men,” I had been engaged in working out, and had 
completed, a treatise upon the same subject, which, 
with a few necessary alterations in nomenclature, I 
afterwards published.* My views for the most 
coincided with those of Presl, but I had paid more 
attention to forming natural groups and bringing 
together species agreeing in their mode of growth, 
and vegetative organs; for it appeared to me that 
pteridologists did not give sufficient importance to 
that point, and even now it is not taken into considera- 
tion as much as it deserves to be. With the exception 
of my own more recent efforts to obtain characters from 
the mode of growth presently to be explained, the only 
further suggestion of any importance remaining to be 
noticed is that of M. Fee, who, in his work on the 
Poli/podiacece, introduced characters taken from the 
form and structure of the sporangia, the number of 
articulations in their rings, and the form of their spores. 
The form of the sporangia, and direction of their rings, 
had previously been adopted by Presl and myself for 
distinguishing the main orders or sub-orders of Ferns, 
and I, in common with all modern pteridologists, still 
rely upon those organs for that purpose ; but I cannot 
consent to their introduction into generic and specific 
characters, as proposed by Fee. Even were the dif- 
* Hook. Joum. Bot., 1841. 
