380 Bower . — A Criticism , and a Reply . 
a detailed comparison : reference only will be made to com- 
munications relating to the Lycopodinae and Psilotaceae 
which have been laid before the Royal Society 1 . In these 
I have brought forward developmental and comparative 
evidence supporting the view that the synangium of the 
Psilotaceae is the result of septation of a Lycopodinous type 
of sporangium, while Isoetes and Lepidodendron provide some 
interesting intermediate features. If this view be correct, we 
should there see examples not only of partial sterilization, but 
of formation of complete septa from the sterile tissue : that is 
of partitioning of the sporangium. This is the third factor 
above alluded to. If this factor occur simultaneously with the 
other two (viz. branching and formation of vascular tissue, of 
which examples have been above quoted, and of which 
incipient steps may be seen in the Psilotaceae), then the result 
might very well be such elaboration as I have suggested that 
we see illustrated in the c fertile frond ’ of the Ophioglossaceae. 
The rather extensive area of facts included in the papers 
above cited will have to be considered by those who are in 
doubt as to my conclusions, and still more by those who appear 
disposed to take an attitude of negation. My conclusions 
as to the part played by spore-bearing members in the 
evolution of the sporophyte may be wrong, and are probably 
susceptible of amendment: my present object has been to 
show that they are not to be disproved off-hand. I have no 
wish to avoid criticism, but I would venture to point out to 
my critics that they are not yet in full possession of the facts, 
or of the reasoning to be based upon them. Till a full 
statement is published, criticism must be more or less 
premature ; it may be accepted as ‘ preliminary criticism,’ in 
the same way as the statements criticized were c preliminary 
statements.’ 
1 Roy. Soc. Proceedings, vol. 1 . p. 265 ; vol. liii. p. 19. Also abstract of the 
detailed memoir, part i. read June 15, 1893. The conclusion of my paper on 
Lepidostrobus Brownii (see above, p. 351, &c. of this volume of the Annals) 
should also be consulted. 
