182 BENEDICT: GENERA OF THE FERN TRIBE VITTARIEAE 
but there is no reason to suppose these would differ from those 
already described for other species of the Vittarieae; it probably 
passes through a similar Monogramma dgreicarpa stage. Very 
likely, too, a second Hecistopteris, i. e., free-veined stage occurs. 
But in no further stage, if A. reticulatum may be taken as typical, 
is Antrophyum like either Vittaria or Polytaenium (PLATE 8, 
FIG. 24-28). 
If the ontogenetic series may be accepted as historically ac- 
curate, Antrophyum is derived perhaps from a form like Hecis- 
topteris and is ‘“‘contemporaneous” with Vittaria, which probably 
had a like origin. Polytaenium, on the other hand, passes through 
a Vittaria stage, and is thus not only on a line divergent from that 
of Antrophyum, but is also of a ‘‘later”’ generation. 
It may be objected that the ontogeny of one species is slight 
evidence upon which to base conclusions for a genus containing 
upwards of twenty-five species. This is a valid objection, but 
it is counterbalanced in this case by the mass of supporting evi- 
dence already adduced, derived from the mature plants. 
MoONOGRAMMA and HECISTOPTERIS 
_I have no data for the ontogeny of M onogramma and none for 
Hecistopteris, unless perhaps some of the smaller leaves of the 
latter genus figured (PLATE 4, FIG. I and 22) represent juvenile 
stages. There is little likelihood, however, that these two genera 
pass through growth stages of a type distinct from the ordinary 
type seen in the other genera. 
Hecistopteris probably begins, as indicated by the two figures 
just noted, with a uninervate Monogramma dareicarpa stage and 
proceeds then by simple dichotomy to the characteristic free-veined 
condition of its mature leaves. In M onogramma it is hardly pos- 
sible that the two simplest species, M. dareicarpa and M. graminea, 
are ever anything but uninervate. It would be interesting to see, 
however, whether the larger species pass through a free-veined 
Hecistopteris stage before reaching the mature areolate condition. 
IV. GENERAL CONSIDERATIONS 
In the foregoing pages, I have endeavored to describe the 
mature sporophytes and the ontogenetic stages of the Vittarieae 
