240 ALTERNATE GENERATIONS. 



extending and contracting their tentacles, some 

 of the heads stretched upwards, others bent 



Single head or branch of Coryne mirabilis, magnified, with two Medusa bud*. 



downwards, all seeming very busy and active. 

 Each tentacle has a globular tip filled with a 

 multitude of cells, the so-called lasso-cells, each 

 one of which conceals a coiled-up thread. These 

 organs serve to seize the prey, shooting out 

 their long threads, thus entangling the victim 

 in a net more delicate than the finest spider's 

 web, and then carrying it to the mouth by 

 the aid of the lower part of the tentacle. The 

 complication of structure in these animals, a 

 whole community of which, numbering from 

 twenty to thirty individuals, is not more than 

 an inch in height, is truly wonderful. In such 



