136 DESCRIPTION OF COPTOPHYLLUM: 
have no definite place of separation from one another, the 
disunion sometimes arising close to the lower divisions of 
the barren part, and sometimes only a little way above the 
rhizoma. In Botrychium Virginicum, the separation, in the 
greater number of instances, occurs immediately below the 
divisions of the barren frond; but, in a specimen in Mr. 
Smith's Herbarium, I find the union of the fertile with 
the barren frond continuing half-way up the rachis of the lat- 
ter; and the case is the same in a specimen of B. lanuginosum, 
in the Herbarium of Sir William Hooker. Such differences 
as these could not exist, were the fertile spikes a modified 
state of some part of the other spike ; for then, the mode of 
separation would be definite. In Ophioglossum there is a 
similar state of things. In that genus, the barren and the 
fertile parts hold the same relative position to one another 
Which they do in Botrychium ; and if we look, for example, 
at O. pendulum, we find that the sterile fronds have no mid- 
rib, while in the fertile there is a dense reticulated central 
mass, which is not continued beyond the separation of the 
fertile spike. How is this produced, if not by the union of 
two fronds? Plumier, in his figure of O. palmatum, repre- 
sents the fertile spikes as coming off from the margins of the 
lower part of the palmated portion of the frond; but in my 
Brazilian specimens, I do not find this to be quite the case. 
In them, it is easy to imagine that there is here also an amal- 
gamation of two fronds; for, in the largest and most perfect 
specimens, the spikes are partly central, and partly situated 
a little within the margin, the marginal ones being the high- 
est, having been carried up, apparently, by the superior de- 
velopment of the barren part. I have no doubt that an 
examination of the anatomical structure of the stipes of these 
plants in the recent state, would prove the correctness of my 
views. 
Kew, Jan. 1842. 
