Strobilus in Archegoniate Plants . 357 
view as the explanation of its origin also. Hitherto the con- 
verse view has commonly been entertained, viz. that synangia 
are the result of coalescence of sporangia in the course of 
descent from an ancestry with separate sporangia ; in fact, the 
whole morphology of homosporous Pteridophytes has been 
dominated by the belief that the Leptosporangiate Ferns are 
the nearest of vascular plants to the Bryophyta. I have 
already stated at length elsewhere my reasons for thinking 
that view to be ill-founded (Annals of Botany, Vol. V. p. 109) : 
however firmly convinced any readers may be of the correct- 
ness of the belief that the Leptosporangiates were the most 
primitive Ferns, and the Ferns the most primitive of vascular 
plants, I would ask them for the moment to relinquish that 
opinion, and contemplate with me an alternative view. 
First, I would state the opinion that, in the course of 
evolution, simple and small-leaved forms preceded complex 
and large-leaved forms ; accordingly, unless there be strong 
reasons against it, we shall be prepared to seek among small- 
leaved, strobiloid, homosporous Pteridophyta for those which 
reflect most nearly the primitive condition. 
Secondly, it would appear that, unless there be strong 
evidence to the contrary, synangia should be recognized as 
the result of septation. The examples above cited from the 
anthers of Angiosperms were treated by writers on the subject 
in the right way ; partly from comparison of allied forms, and 
partly from the study of development, it was concluded that 
the anthers had become septate owing to a partial sterilization 
of potential sporogenous cells. The same has been concluded 
in the case of the trabeculae of Isoetes. A similar course 
should be taken with the synangia of Psilotaceae, Filicineae, 
and Ophioglossaceae ; but I would premise that in plants 
where, as in these, the meristems are not disposed in definite 
strata, the recognition of a potential archesporium as a definitely 
limited and continuous band of tissue must not be too 
rigorously demanded before the synangia be admitted as 
results of septation. The facts which have been acquired 
relating to the Psilotaceae have already been stated at length 
