298 Bower . — Some Normal and Abnormal 
Goebel’s ideal £ oldest type,’ in which the sexual organs are 
inserted directly on the filament. 
As regards the archegonia themselves, they correspond so 
closely to those of other Ferns as to supply no special evidence 
of a relation to other groups ; thus (discounting the difficulty 
as to details of development of the antheridium) the sexual 
organs are more constant in their characters, and especially 
in their mature structure, than is the general conformation of 
the thallus, and accordingly greater weight should be attached 
to them than to the vegetative thallus in drawing phylogenetic 
conclusions. A comparison of these, on the one hand, with 
those of the other Ferns, and, on the other, with those of 
the Bryophyta, shows that, in respect of the sexual organs, 
the Hymenophyllaceae hardly approach nearer to the Bryo- 
phyta in any appreciable degree than do other Ferns. 
Abnormal Characters. 
Passing now to the abnormal characters, we see in Tr. 
alatum and Tr. pyxidiferum two fresh examples of apospory , 
accompanied by partial, though not complete sporal arrest. 
There are many points of similarity between these new cases and 
those of the Ferns described in my former paper on Apospory 1 ; 
thus, the direct vegetative outgrowth of prothalloid ex- 
pansions from the tips of the pinnae in Tr. alatum (Fig. 30), 
without there being any clear limit between the sporophyte 
and the oophyte, is closely comparable with the case of 
Polystichum angular e , var. pulcherrimum there described and 
figured 2 ; again, the outgrowths from the surface of the frond 
(Fig. 28), and perhaps also from the sporangium itself 
(Fig. 29) in Tr. alatum find their parallel in the Polystichum . 
Even in the filamentous nature of some of the outgrowths of 
the Trichomanes (Fig. 27) a certain analogy may be traced 
to such growths as those shown in Polystichum 3 . It 
will be further noted that the outgrowth in Tr. alatum 
3 Linn. Trans. Vol. ii (1887), Part 14. 
3 1. c. Fig. 36. 
2 1. c. p. 308, Plate lviii. 
