254 P r anker d. — On the Structure and Biology of 
for the statement that Hottonia is £ free-floating ’ (8), and the idea that land 
forms are quite distinct from ordinary aquatic individuals. A little care 
will show that the stem is nearly always attached, and where this is not 
the case, it has probably become detached from accidental causes (children, 
water animals, &c.). Similarly, in the case of the land forms, it is possible 
that they may sometimes be produced in some way other than that de- 
scribed, e. g. the germination of seeds ; but I have never found them more 
than a few feet from the water, and frequently traced them to underground 
stems, various stages of decay often occurring in the intervening portions. 
The land form is sometimes considerably branched, the aquatic stem rarely 
so, except at the surface of the water, where a whorl of some six or eight 
branches is formed at the base of the inflorescence. In the young plant, 
these are often several centimetres in length, before the elongation of the 
inflorescence axis ; and throughout the life of the latter undoubtedly help 
Text-fig. i. Diagrammatic sketch of typical plants of Hottonia palustris. 
to secure its vertical position. After fruit formation, these branches separate 
from the parent plant, rest through the winter, and form the starting-points 
for new plants the next spring, when they may be found truly free floating, 
and often without roots. This immature stage is the only one that may 
answer to Schenk’s description of Hottonia as rootless (8), which is entirely 
incorrect for the full-grown plant. Of the scores of plants examined from 
various localities round London, I have never found a single mature rootless 
specimen, and Brokschmidt reports similarly of the specimens from the 
ponds of Dechsendorf, Germany. Hottonia produces very numerous 
adventitious roots along the whole length of the stem, particularly in the 
underground part and at the base of the inflorescence. They may appear 
in any position, but are most often found just above the insertion of the 
leaves, or of the axillary buds, if these are developed. They are long, 
slender, and unbranched, often reaching the soil and thus serving to anchor 
the plant. 
