222 The Philippine Journal of Science 1914 
In both genera the superficial dorsal cells of the sporangium 
are dark brown in color, due to the presence of dense cell- 
contents which probably contain tannin, and which stain very 
strongly with safranine (fig. 3). In Angiopteris these tannin 
cells cover the entire dorsal surface, but in Macroglossum Alidae 
they are absent from the dorsal region for nearly half the height 
of the sporangium. M. Smithii is intermediate between Angiop- 
teris and M. Alidae in this respect. 
Similar brown cells are also found upon the inner or ventral 
face of the sporangium in Angiopteris, forming a band on each 
side of the line of dehiscence, and extending to the base of the 
sporangium. In Macroglossum Smithii two patches of these 
cells occur on either side of the line of dehiscence near the apex 
Fic. 3. A, median sections of the sporangia of Macroglossum Alidae; B, Macroglossum 
Smithii; C, Angiopteris evecta (7); an, annulus; t, tapetum. The tannin cells are 
shaded. X about 75. 
of the sporangium, but in M. Alidae they are entirely wanting 
on the ventral face of the sporangium. (Fig. 3, A.) 
In Angiopteris a conspicuous annulus (fig. 4, C, an) of lig- 
nified cells occupies the apex of the sporangium. In Macro- 
glossum Smithii, a similar, but much less evident annulus occurs; 
but in M. Alidae, this is almost entirely wanting. 
These differences, i. e., the form and anatomy of the leaf; 
the structure and arrangement of the sporangia and indusium, 
would seem amply sufficient to separate Macroglossum from 
Angiopteris. Of the two species M. Alidae may be considered 
to be less specialized in regard to the sporangium. The num- 
ber, arrangement and structure of the sporangia are more like 
Archangiopteris than like Angiopteris, and on the whole, Macro- 
glossum may be considered to be most nearly related to the 
former genus. Like Archangiopteris there are suggestions of 
a possible relationship with Danaea; but the entirely separate 
