308 Bower . — The comparative examination of the 
struction ; then the rest of the leptosporangiate Ferns 1 , with 
the Schizaeaceae as a group leading towards the Osmundaceae, 
which in turn lead on to the Marattiaceae. 
The material necessary for this investigation is for the most 
part rare : the specimens of Trichomanes and Hymenophyllum , 
as well as some others, have been supplied from Kew, and 1 
wish to record my thanks to the Director of the Royal Gardens 
for this, and for the use of the Jodrell Laboratory, in which 
much of this work was conducted. Other specimens were 
derived from the Glasgow Garden, while the specimens of 
Marattia and Angiopteris were from my collections made in 
Ceylon. 
Apices of Roots. 
I am not aware that any observations of the structure of 
the apex of the root in any of the Hymenophyllaceae have 
been recorded, beyond the remark of Prantl 2 that one conical 
apical cell is present in Gonocormus ( Trichomanes ) dichotomus , 
which he figures in longitudinal optical section in his Plate I, 
Fig. 8. I have had the opportunity of observing the apex of 
the roots of Trichomanes radicans , and of Hymenophyllum 
demissum : in both of these the structure was found to con- 
form to the normal type for the root of leptosporangiate 
Ferns, as described by Naegeli and Leitgeb 3 , and accordingly 
there is no need here for a special description or for figures : 
it may, however, be remarked that the structure as shown in 
Prantl’s Fig. 8, above quoted, does not convey the impression 
of the exact sequence of the cell-divisions being normal ; but 
as the figure was drawn, not from a section, but from an apex 
cleared by reagents, and seen in optical section, the slight 
discrepancy need be no obstacle to the conclusion that the 
1 I do not think it necessary for the present argument to arrange these lepto- 
sporangiate Ferns in any definite sequence, since their relation to one another is still 
uncertain, while the construction of their meristems appears to be almost uniform. 
2 Unters. z. Morph, d. Gefasskrypt. Heft I, p. 31. 
3 Beitr. z. wiss. Bot. Heft IV, 1868. 
