THE II YD HO ID MEDUSAE. 
339 
originate on a special offshoot (a quasi flower-stalk), which is 
now naked, and now protected by a transparent urn ; sometimes 
they spring singly or in clusters from the body of the polypite ; 
sometimes they pullulate from a portion of the common sub- 
stance which links together and binds into one organism the 
many zooids composing a colony. 
Let us examine a cluster of them, hanging from the body of 
one of the naked polypites. Commonly each bud is inclosed 
in a delicate capsule, which protects but only half conceals 
the exquisite structure that is ripening into perfect form 
and ” tender grace ” within it. In some cases, however, this 
envelope is wanting, and the bud is freely exposed through 
the course of its evolution to the surrounding water. In each 
cluster we find buds in all stages of development ; but one is 
always much in advance of the rest, and attains maturity while 
some of its companions are merely rudimentary. And here let 
me pause for a moment to celebrate the beauty of the group of 
animal flower-buds, already showing traces of the vivid colour- 
ing that adorns the adult medusa ; some closely folded up, and 
giving scarce a hint of the marvellous form that is being 
moulded within, some heaving with the pulsations of the 
imprisoned zooid, while one, it may be, has opened, and the full- 
blown medusa is visible hanging from its slender pedicle, and 
struggling with the bond that still detains it. 
Through the investing capsule the general form and leading 
features of the contained zooid may be dimly traced ; but so 
tightly is it packed in its little case, and so much are the parts 
compressed and thrown together, that it is difficult to realize 
its appearance until it emerges from its captivity. In the 
later stages of development, the contractile movements that 
are so characteristic of the tribe become frequent and vigorous, 
and at length the capsule is ruptured, and the medusa unfolds 
itself ; the tentacles, which had been stowed away within the 
swimming-bell, are cast forth, the bell itself assumes its true 
proportions, and it hangs as if on the point of starting into free 
life. But it is still attached, and arduous and often protracted 
struggles must precede its final liberation. 
Up to this point that portion of the bud which is to form 
the digestive sac of the medusa has been in direct connection 
with the common cavity of the zoophyte, and has received from 
it constant supplies of nutriment. But the communication is 
now to cease, and all the energies of the zooid are engaged for 
the time in severing the link that binds it to the common life 
of the colony. ( Vide Plate LXXXVIII., fig. 3 ; a marks the point 
at which the medusa was attached, and in communication with 
the general chymiferous cavity.) The struggle for freedom is 
often long, and, to the watching naturalist, wearisome enough ; 
the bell contracts and expands rapidly, jerk succeeds jerk, tug 
