4 Bower.—Studies in the Phytogeny of the Filicales. VII . 
appearing at the dilated nodes as it does, there is by this means a readjustment 
of the balance of the intrastelar tissues. If the latter view be accepted, then 
(i) 5 . pusilla , rupestris , and fistidosa , (ii) 5 . malaccana , and (iii) S. dichotoma 
would illustrate steps in structural advance of the adult from the protostele 
actually seen in the juvenile stem to an imperfect solenostely. 
In none of these is any internal phloem present. But in Anemia it is 
seen, with the result that in the creeping species (§ Anemiorrhiza :) a typical 
solenostele is constituted, as in A. adiantifolia and aurita. In the upright 
species, however, the leaf-gaps overlap on the abbreviated axis, and typical 
dictyostely results. This is seen in A. phyllitidis, and also in Mohria. The 
successive steps are summed up in the ontogeny of A. phyllitidis , as 
described by Boodle, 1 and early conditions are shown by Fig. 3, i-iv. 
These early stages are seen to compare with those of Schizaea rupestris. 
But later, as shown by Boodle, 2 an internal phloem appears, giving what is 
described by Tansley as the Lindsay a- structure. It is quickly followed by 
internal endodermis giving the state of solenostely. 
Thus in the Schizaeaceae, more clearly than in any other family of 
Ferns, the successive steps between protostely and dictyostely are illustrated 
both in the ontogeny and in the mature state. Those of the more 
advanced types which have been investigated show more or less clearly in 
their ontogeny such successive steps of increasing complexity. It is then 
possible to interpret the adult structure of the less advanced types as having 
stood still before the progression was completed. This point of view will 
have its value in the comparative study of the Pterideae. 
Prantl demonstrated, by hand preparations from all the genera of 
Schizaeaceae, that the origin of the sporangia is from the marginal cells of 
the young pinna. This conclusion has since been confirmed for Lygodium 
by Binford, 3 and for Anemia by Stevens. 4 I have found his conclusion 
upheld by sections of the young leaf of Mohria , though the marginal 
position is soon disguised. The question is, however, still open for 
revision in the case of Schizaea. 
In the Synopsis Filicum (p. 428) this genus is divided into \Euschizaea , 
with frond terete and capsules biseriate: §§Lophidium } with frond flattened 
and capsules biseriate: and §§§^4 ctinostachys, with fertile segments digitate 
and capsules quadriseriate. Already Prantl had investigated S.pennula , Sw., 
which falls into §§§ Actinostachys , and he found that the sporangia originate 
on the margin as a single row on each side. 5 He suggested that their 
appearance as in four rows when mature is due to subsequent displacement. 
He found them to be covered by indusial flaps, which arise from the upper 
leaf-surface immediately behind the actual margin, while the sporangia 
themselves are thereby deflected towards the lower surface. 
1 1 . c., p. 389. 2 1 . c., vol. xv, PI. XX, Figs. 27-30. 3 Bot. Gaz., vol. xliv, p. 214. 
4 Ann. of Bot., vol. xxv, p. 1059. 6 1. c., p. 45, PI. V. 
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