There is evidence that each of the two broods which occur in Lower
Bengal represents at least one generation; probably it represents more
than one, for tentacles are rarely if ever produced after the animal has
obtained its full size, and never (or only owing to accident) decrease
in number after they have once appeared. The winter form is found
chiefly near the surface of the water, especially on the roots of
duckweed and on the lower surface of the leaves of _Limnanthemum_; but
the summer form affects deeper water in shady places, and as a rule
attaches itself to wholly submerged plants. The latter form is to be met
with between March and October, the cold-weather form between October
and March, both being sometimes found together at the periods of
transition. In the unnatural environment of an aquarium, however,
individuals of the winter form lose their colour and become attenuated,
in these features resembling the summer form, even in the cooler months.
Buds produced in these conditions rarely have more than five tentacles
or themselves produce buds freely after liberation.
The buds appear in a fixed order and position, at any rate on
individuals examined in winter; in specimens of the summer form the
position is fixed, but the order is irregular. Each quadrant of the
column has apparently the power of producing, in a definite zone nearer
the aboral pole than the mouth, a single bud; but the buds of the
different quadrants are not produced simultaneously. If we imagine that
the quadrants face north, south, east, and west, and that the first bud
is produced in the north quadrant, the second will be produced in the
east quadrant, the third in the south, and the fourth in the west. It is
doubtful whether more than four buds are produced in the lifetime of an
individual, and apparently attached buds never bud in this race. The
second bud usually appears before the first is liberated, and this is
also the case occasionally as regards the third, but it is exceptional
for four buds to be present at one time. About three weeks usually
elapse between the date at which the bud first appears as a minute
conical projection on the surface of the parent and that at which it
liberates itself. This it does by bending down, fixing itself to some
solid object by means of the tips of its tentacles, the gland-cells of
which secrete a gummy fluid, and then tearing itself free.
Public-domain text, read in full here on John Shaqi.
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