GENERAL MORPHOLOGY 439 
and the three separate spikes are inserted by sterile pedicels upon a 
common sterile stalk. Thus the branching, though less common, appears 
to be similar in kind to that in O. palmatum. 
Somewhat similar branchings, though*less complete, are not uncommon 
in O. vulgatum. In the Kew Herbarium there are certain abnormal speci- 
mens which are of some interest in this connection. Fig. 239 J represents 
a plant of O. vulgatwm taken in wet fields at Farnham, Surrey; from the 
upper surface of the sterile frond arise three fertile spikes, one of which 
is branched, while the point of insertion of another is at some little distance 
from the remaining two, which are seated close together. Though the 
details of insertion are not identical, this may be compared with the Fig. 
238 E of O. palmatum, or as regards insertion of the spikes with Fig. 238 pb. 
Another, and much larger specimen, showing a somewhat similar abnormality 
of O. vulgatum, is seen in Fig. 239K; there are two leaves from the same 
plant, each bearing three fertile spikes, which have, however, a common 
insertion. Somewhat similar monstrosities are mentioned, as occurring 
rarely, by Luerssen.! 
In the Kew collection specimens of O. veticulatum also show abnor- 
malities of a similar nature, though the branching is less complete: and 
these specimens will serve to show that such abnormalities cannot be used 
to support the view that the fertile spike is a result of fusion of two 
pinnae. One specimen from the Society Islands (Bidwell, Herb, Hook) 
shows an equally bifurcated fertile spike, with a long sterile stalk: this 
might appear to support the hypothesis of coalescence; but another speci- 
men from Java (Lobb, Herb, Hook) shows three branches, of which the 
central one is the strongest; comparison should also be made of Figs. 239 
J, K of abnormalities in O. vudgatum; such cases as these would be entirely 
inconsistent with the theory of coalescence as supported by abnormalities. 
It must therefore be concluded from the genus, as we should already have 
judged from the cases of O. palmatum and O. pendulum, that the forms 
which the fertile spike occasionally assumes, gives no constant support to 
the hypothesis of coalescence of lateral pinnae. This being so, and taking 
also into account generally the facts of branching and insertion of the 
fertile spike or spikes in the genus, the hypothesis that the fertile spikes 
are of the nature of pinnae or leaf-segments appears to receive no consistent 
support. On the other hand, all the facts are consistent with an hypothesis 
of chorisis of a single original spike, holding a median adaxial position: 
and it may be concluded that in OpAzoglossum a fission, occasionally seen 
in such species as O. vulgatum, has become habitual in O. palmatum, and 
in less degree in O. pendulum. This is interesting for comparison with 
what is seen in certain of the Sphenophyllales, where fission of the 
sporangiophore appears to have occurred. 
But ‘besides such probable amplifications within the genus, there is 
also a line of probable simplification: it is seen in the new species, 
1Rab, Arypt. Flora, vol. iii., p. 544. 
