198 
THE OCEAN WORLD. 
filaments liaye sacs and canals containing fluids at tlieir roots. Suckers 
are also found at the extremities, and along the sides of these tentacles 
in several genera are suckers, by which they are able more securely to 
catch their floating prey, or to anchor themselves when at rest. The 
indications of nerves or nervous system are too slight to be received as 
evidence, although Dr. Grant observed some structure which he thought 
could only belong to a nervous system, and Ekrenberg thought he ob- 
served eyes in Medusa aurita, as well as a nervous circle formed of four 
ganglion-like masses disposed round the mouth. But most naturalists 
seem to be of opinion that touch is the only sense of which any con- 
clusive proof can be advanced. 
Here we behold a class of bell-shaped semi-transparent organisms, 
which float gracefully in the sea — a great family of fragile, wandering 
animals, constituted in a most extraordinary manner. They look like 
floating umbrellas, breeches, or, better still, floating mushrooms, the 
footstalk replaced by an equally central body, but divided into diver- 
gent lobes at once sinuous, twisted, and fringed, so that one is at first 
tempted to take them for a species of root. The edges of the umbrella 
or mushroom are entire or dentate, sometimes elegantly figured, often 
ciliate, or provided with long filiform appendages which float vertically 
in the water. 
Sometimes the animal is uncoloured, and limpid as crystal ; some- 
times it presents a slightly opaline appearance, now of a tender blue, 
or of a delicate rose colour ; at other times it reflects the most brilliant 
and vivid tints. 
In certain species the central parts only are coloured, showing 
brilliant reds and yellows, blues or violets, the rest being colourless. 
In others the central mass seems clothed in a thin iridescent or 
diaphanous veil, like the light evanescent soap-bubble, or the trans- 
parent glass shade which covers a group of artificial flowers. 
The Acalephse are animals without consistence, imbued with much 
water, so that we can scarcely comprehend how they resist the agita- 
tion of the waves and the force of the currents ; the waves, however, 
float without hurting them, the tempest scatters without killing them- 
When the sea retires, or they are withdrawn from their native waters, 
their substance dissolves, the animal is decomposed, they are reduced 
to nothing ; if the sun is ardent, this disorganisation occurs in the 
twinkling of an eye, so to speak. 
