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 instance, 

 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 Actinia, 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, 



