Bower v — Studies in the Phytogeny of the Filicales . VI. 27 
but little removed from the oblique, and the spores of both are tetrahedral. 
But the sporangium of Syngramme has a three-rowed stalk, as against the 
four-rowed stalk of Metaxya . Both genera have hairs, and not scales, 
as dermal appendages. Unfortunately the comparison could not be tested 
by vascular anatomy, but from herbarium material it appears that Syn- 
gramme has three separate strands in the base of the petiole, which is 
a structural advance on what is seen in Metaxya. Thus the facts appear to 
support the suggested affinity, the points of difference being those charac- 
teristic of a phyletic progression parallel to what has been repeatedly seen 
in other phyla. In subdivision of the leaf-trace, the anastomoses of venation, 
extension of the sorus, and in the three-rowed stalk of the sporangium 
Syngramme shows characters of advance on Metaxya. 
E lapkoglossum. 
In his monograph of the genus E lapkoglossum 1 Christ plainly states his 
opinion that this genus is far removed from other Acrosticheae. The only 
Ferns which he recognizes as resembling them are those of the genus 
Text-fig. 13. Elaphoglossum latifolium. a , Rhizome in transverse section, showing only 
one leaf-gap ; b, ditto, showing two leaf-gaps x, Y, while from the largest meristele the vascular 
supply is passing off to a bud {b ) ; c, transverse section of base of petiole, x 4. 
Syngramme. Their habit is the same, as also their venation. The chief 
difference consists in the sporangia of Syngramme forming elongated sori 
following the veins. If in Ferns of the type of Syngramme the sporangia 
were spread over the whole surface, then such types would rank as Elapho- 
glossum. The comparison of these genera may be extended to other 
characters besides those named. Transverse sections of the rhizome of 
E. latifolium (Sw.), J. Sm., collected in Jamaica, are represented in Text- 
fig. 13. It shows vascular structure nearly approaching a solenostele (a), 
but with leaf-gaps sometimes overlapping (b). The leaf-trace (e) is much 
subdivided, and it is so from the first, being given off as distinct strands (a, b), 
of which the median separate first. Their arrangement suggests comparison 
with a fully solenostelic type, such as Metaxya , from which the structure 
could readily be derived by perforation of the leaf-trace and continuation of 
the perforations downwards to the rhizome. Like Metaxya , Lophosoria , and 
1 Denkschr. d. Schweiz. Naturf. Ges., Basel, 1899, pp. 14-18. 
