JELLYFISH.
75
at times lives at some height above the bottom, but quiet deep
waters are essential for its protection. It may be because of its
low budding capacity and low strobilation numbers, coupled with
the cannibalistic nature of its Medusa, that the planulae are
liberated in such myriads.
Of the Cyaneas, both capillata and Lamarckii bud about
equally,7 but the former rather likes sunlight and Lamarckii
dislikes it; moreover, capillata produces very thick strong
stolonic processes, and does not detach itself. It is often
attached at two or three distinct parts of its base, whereas
Lamarckii, in my experience, in stagnant water detached in such
numbers as to be a nuisance. I have argued with myself that
these characteristics appear to show that capillata is a form
living much nearer the shore or at least in much shallower
water than does Lamarckii. It is fairly certain that it is rare
for the two forms to be found in numbers together.
Hydra tubae, without exception, reproduce by budding,
and one form only—so far as I have seen—(Type 3, Aurelia)
produces resting cysts or buds which evolve away and apart
from the parent. In all other cases the life of the parent Hydra
Tuba passes directly into the bud, as is shown by the fact that
when attached to the parent the time of growth is four days
and that when separated from the parent 14 days are necessary
to attain to the same stage of development. There are three
ways of budding, viz.:—
(1.) By direct growth from the outer wall of the body with,
generally, early liberation.
(2.) By means of the lateral process with immediate libera-
tion ; and
(3.) By means of stolonic outgrowths, the buds sometimes
being liberated but more often remaining as colonies
surrounding the parents.
All three forms are found in Aurelia in its various types.
Chrysaora buds by the lateral process alone, Rentoni by the
lateral process alone, Cyanea capillata budding chiefly by stolons
and being colonial in habit. C. Lamarckii is mostly solitary,
the buds moving away.
Owing, however, to the unforeseen difficulties arising from
the continual infections of Cyanea, the writer considers that his
7 C. capillata sometimes produces buds from au upright stalk as with the Hydroids.