730 Henslow.—The Origin of Monocotyledons from Dicotyledons , 
This is then ‘ caught’ within the broad or sheathing base of the single 
petiolate cotyledon. 
This retention of the bundle from a lost organ may be paralleled by 
those of the five lost stamens being retained within the perianth segments of 
the flowers of Orchids. 
This does not alter the fact that the organs, the cotyledon, and the 
stamens are suppressed. 
Moreover, one cotyledon may be suppressed, but it does not necessarily 
follow that its representative strand should pass into the sheathing base of 
the one developed. 
The rudiments of abortive cotyledons remain in Ceratozamia and Trapa , 
and also in the Oat; but no cord belonging to the lost one enters the 
developed cotyledon. 
In Ranunculus Ficaria,l rmisch figures the petiole of the single cotyledon, 
showing the sections of the midrib and two marginal strands characteristic 
of most dicotyledonous leaves. 1 Bunium is simpler in having only one 
central strand. 2 Anemone apennina has the two blades of the cotyledons 
sometimes coherent half-way up. Then the two strands are included, but 
diverge as midribs. 3 
With regard to Ranunculus Ficaria , I have noticed some other features 
than those mentioned in my former paper as indicative of an ancestral 
aquatic habit. 4 
Both the upper (as on floating leaves) and lower epidermis are provided 
with stomata ; while the cells of the lower have a wavy or indented outline, 
each has a cluster of chlorophyll granules in it. The cells on the upper 
have much less irregular walls, and are devoid of chlorophyll. The guard 
cells of the stomata are provided with chlorophyll. 
The leaves have been described as ‘opposite’ (Hooker), but while the 
first two leaves on the flowering stem appear to be a pair of leaves, i. e. one 
opposite to the other, the sheathing base of one overlaps that of the other. 
Other leaves on the same stem are single. 
The phyllotaxis, therefore, is This arrest of an internode between 
the first two leaves on a vigorously growing, erect stem is perhaps, the result 
of a habit not yet quite abandoned, when the stem was enabled to grow, 
on the plant becoming terrestrial. The leaves were doubtless originally 
crowded together, as is more generally the case now, arising from a very 
short thick ‘ stock ’, giving the ‘ squat ’ habit to the Lesser Celandine, growing, 
as it usually does, in damp soils. 
1 Beitrage zur vergleichenden Morphologie der Pflanzen, Parts I and II (1854). 
2 Irmisch, op. cit. 
3 Miss Sargant mentions Ranunculus chius, R. repens, Phlomis , Urtica. &c., as having been 
found with the two blades of the cotyledon more or less united, but it is in all cases exceptional or 
‘ monstrous 1 . 
4 loc. cit., p. 495. 
