22 HYDROIDS, ETC. 
they resemble cylinders attached to the bottom, the oppo- 
site end containing the mouth, which is surrounded by 
numbers of hollow tentacles, armed with lasso-cells (Fig. 
21), while near the base of the tentacles are the minute 
Fic. 20,—Anemone with ten- 
tacles expanded, attached 
by sucking disc to the bot- Fic. 22.—Cross-section of anem- 
tom. one, showing septa. 
eye-spots. If a dead anemone that has become somewhat 
hardened is cut open horizontally, we first notice the stom~ 
ach, that, divided into mouth and stomach proper, seems 
suspended in the body, held in place by six partitions 
(Mesenteries) (Fig. 22), that also divide the body cavity 
into as many distinct chambers. Each of the six prin- 
cipal partitions is perforated with an opening, and the 
chambers connect with the tentacles, so that water, and 
food captured by the tentacles, is taken in at the mouth, 
and penetrates, by the opening at the bottom of the stom- 
ach, to every part of the animal. 
The anemones vary greatly in size, from delicate un- 
attached forms that live up among the folds of the great 
jelly-fish Cyanea to enormous ones two feet across. The 
