62 LIFE AND HER CHILDREN. 
of the large jelly-fish of the sea ; for after watching 
the floating- bells we cannot doubt that those enor- 
mous jelly masses which we see sailing along in the 
ocean are their near relations. Indeed, those who 
swim and bathe in the sea can testify feelingly to the 
power of the poisonous lassos, for to be stung by a 
jelly-fish is no slight matter, and this sting is given 
by the lasso-cells. 
Though jelly-fish, however, are uncomfortable to 
meet in the water, they are most interesting to watch 
from a boat, or the head of a pier, as they move 
along dome foremost, w T ith a regular movement, as if 
by clockwork. We scarcely realise how large they 
are, till coming close to them we lay an oar over 
them, and find perhaps that the dome measures a 
foot and often tw r o or three feet across, while their 
tentacles stretch from the head to far beyond the 
stern of an ordinary boat. From spring to late 
autumn they may be seen when the weather is calm, 
sailing on the water, not by means of a veil like the 
jelly-bells, for they have none, but by the movements 
of their huge umbrella, which they contract when 
storms arise, and so sink down into the depths. 
What is the history of these huge soft masses ? 
First we must notice how very little solid matter 
life has to use in building up their bulky forms, for 
when a jelly-fish of four or five pounds' w r eight is cast 
on shore and dried up by the sun, a film weighing a 
few grains is all that remains ; the rest was all water! 
Yet the creature is wonderfully made. Take for in- 
stance the jelly-fish shown in Fig. 23. Its tawny, 
yellowish umbrella is full of canals carrying the 
nourishment over the whole animal. In its margin 
