through Self-adaptation to a Moist or Aquatic Habit. 731 
Professor Hugo de Vries 1 has shown by experiment that there are three 
causes which give rise to annuals ; that is, they hasten the production of the 
central stem, viz. freedom of growth, by the absence of crowding, insolation, 
and a rich soil. Conversely, we may assume that crowding, shade, and a 
poor soil, besides water, may be expected to produce ‘tufting’ rosettes 
and a ‘ squat ’ habit. 
The phyllotaxis of the Lesser Celandine suggests the origin of the three 
sepals and eight or nine petals, as the normal numbers. The absence of 
fives being accounted for by the single cotyledon and the J arrangement of 
the leaves, these alone cannot give rise to the § arrangement. 
It has also been noticed that the fibrovascular bundles or strands are 
£ closed’ as in Monocotyledons. This will be referred to again, as recorded 
by Professor Vines. 
In allusion to Rammculus Ficaria , Corydalis cava , and Carum Bulboca- 
stanum , Miss Sargant observes that ‘ the embryo of all these species is very 
little developed in the ripe seed. A long period of maturation is necessary 
before germination can take place. In each, the single cotyledon was 
certainly derived from two ; the ancestral genera certainly had two.’ 
‘ The actual process in all three forms bears a strong resemblance to 
the development of the embryo in Tamus. The cotyledon appears on the 
flattened apex of the pro-embryo as a peripheral ridge [this also occurs 
in Castalia, &c.]. At first it is circular, but it soon becomes crescent shaped 
by the rapid growth of one side. The stem apex is often late in appearing. 
It is always formed in the central depression outlined by the circular ring. 
Very soon the stem-bud is completely dominated by the lateral member, 
which embraces, and at last arches over it. This lateral member is, of 
course, the single cotyledon which becomes apparently terminal in the 
mature embryo, for it manages to push the stem apex to one side. In the 
interpretation of their results, Hegelmaier and Schmid consider one possi¬ 
bility only—the formation of a single cotyledon from the original pair by 
suppression of the second.’ 2 
11. The Effect of Water upon Roots. 
An ordinary dicotyledonous seedling growing in moist soil develops its 
primary root normally, and frequently to a great length, as under cultivation, 
the presence of water acting as a stimulus. Thus a turnip root, finding its 
way into a field drain-pipe, elongated to an extent of upwards of six feet. 
If, however, seeds of Dicotyledons be grown in a net over water, as 
soon as the radicles penetrate it, they perish. Adventitious roots now 
appear from the hypocotyl. This arrest of the axial root is characteristic 
1 Alternating Annual and Biennial Habit : The Mutation Theory, vol. ii, p. 291, P. 25. 
2 Reconstruction, &c., pp. 156-7. See refs, in Miss Sargant’s References to Literature, op. cit., 
p. 183. 
