376 Bower . — The comparative examination of the 
extends to the sporangia of Equisetum and to Lycopodium , 
and Selaginella , and it is still maintained by him in com- 
paratively recent writings 1 . Now we have seen that the 
transition from leptosporangiate to eusporangiate forms is 
effected with the transitional step of the Osmundaceae within 
the Filicineous series, and without any lateral coalescence of 
simpler sporangia being necessary to bring it about ; therefore, 
the eusporangiate sporangium is not in all cases a ‘sporocyst.’ 
To me the view that it ever is seems to be quite unnecessary 
and improbable : it is a much more simple interpretation of 
the deeply seated sporangia of Ophioglossum to regard each as 
a true sporangium, in which the shortening of the stalk, 
widening of the insertion, thickening of the wall, and increase 
in number of spores, are all carried to a still higher degree than 
in the Marattiaceae. To argue on such a point across from 
the Filicineae to the Lycopodineae and Equisetineae appears 
to me to proceed on the assumption of a much nearer relation- 
ship of these series than a comparison of their characters will 
justify: again, in their case I think that the view of their 
sporangia as coalescent { sporocysts 5 is ill-founded. 
On comparing the different vegetative members of the plant 
as seen in the series of Ferns, it will be found that as we rise 
in the series certain members retain the single initial more per- 
sistently than others. This will be seen from the following 
table, in which the numbers refer to the number of initial 
cells observed in each case : — 
Hymenophyllaceae 
Root. 
1 
Stem. 
I 
Leaf. 
Polypodiaceae, etc. 
1 
I 
1 
Schizaeaceae .... 
1 
I 
1 
~ , \ (1) Osmunda 
Osmundaceae 1 w 
i -3 
i (rarely more) 
I 
( (2) Todea 
usually 4 
— 
1 
Marattiaceae j ^ ^arattia . 
apparently 4 
4 (or more) 
1 (or more) 
( (2) Angioptens. 
4 
4 (or more) 
3 (or more) 
From this it will be gathered that in the series of plants named, 
1 Angiospermen und Gymnospermen, p. 53, footnote 4. 
