234 HISTORY OF BRITISH ZOOPHYTES. 
flower zoophytes, because they give us a good idea of the 
beauty and the structure of those coral zoophytes in tropical 
seas, remarkable for their beauty, and still more for their ex- 
traordinary operations. One advantage that we derived 
from dwelling a little on the way in which the naked green 
Hydra increased by buds and branches, was, that it led us to 
know more of the way in which the Sertularia, for stance, 
increased, though the animal was not seen under its calca- 
reous covering. In the same manner, by the study of our 
British unclothed sea-anemones we are prepared for forming 
a good idea of the coral-working zoophytes of foreign seas, 
many of which greatly resemble our native Actiniz, though 
they can, at will, conceal themselves from our notice by re- 
treating into the beautiful habitations they have formed. 
Our own Actinia@ are like Colchicums, or autumnal crocuses, 
as they are called, which send forth their showy blossoms 
from the earth, without even a green leaf to protect them ; 
the coral zoophytes are more like a flowering shrub, whose 
blossoms are defended by branches and leaves, while they 
have this advantage over the shrub, that they can not only 
fold their petals, but can retreat for safety into their cells. 
A French writer, Le Sueur, speaks in rapturous terms of the 
coral zoophytes of warmer climes: ‘“‘ When the sea is calm, 
