SQUIRTS, POLYPS, AND JELLY-FISHES. 65 
the sun, and in a short time it will have almost com- 
pletely disappeared through evaporation. Whence 
came these singular creatures, and whither do they 
go? The greater number of them begin life in a 
quiet way as minute buds on the stems of the cam- 
panularians and their allies. After expanding and 
acquiring definite shape they drop off from the 
parent, and pass into that stage which fits them for 
a free existence on the oceanic surface. The me- 
dusa thus formed for some time leads the life of 
an independent rover, but after a certain period it 
gives birth from eggs to elongate tiny bodies, known 
as planule, which soon attach themselves and grow 
up into the grandparental form of the hydroid 
colony. Thus a complete cycle of changes is 
brought about. Some of the meduse give birth 
directly to other medusze, without passing through 
any of the intermediate conditions that have just 
been noted. , 
The transition from the delicate sea-bubbles, 
whose existence, it would seem, could be wiped 
out by amere blow of the breath, to the large un- 
sightly jelly-pads that lie scattered over the shore 
after high-water, is an abrupt one, but yet the two 
objects are much the same thing. One is merely a 
large jelly-fish, while the other is a small one. But - 
on the open sea even the large Cyanea, whose disk 
or bell measures two yards in diameter, and whose 
wilderness of tentacles floats out to a distance of 
a hundred feet or more, is a beautiful object, re- 
flecting its brilliant tints of pink, yellow, blue, and 
brown to striking advantage. When cast on the 
e 6* 
