260 ALTERNATE GENERATIONS. 
Hydre ; but, beside these, there are certain mem- 
bers of the community who act as swimmers, to 
carry it along through the water, — others that 
are its purveyors, catching the prey, by which, 
however, they profit only indirectly, for others 
are appointed to eat it, and these feeders may 
be seen sometimes actually gorged with the food 
they have devoured, and which is then distrib- 
uted throughout the community by the po 
of digestion and circulation. 
It would be hopeless, even were it desirable, 
to attempt within the limits of such an article 
as this to give the faintest idea of the number 
and variety of these Hydroids; and I will there- 
fore say nothing of the endless host of Tubula- 
rians, Campanularians, Sertularians, etc. They 
are very abundant along our coast, and will well 
reward any one who cares to study their habits 
and their singular modes of growth. For their 
beauty, simply, it is worth while to examine 
them. Some are deep red, others rosy, others 
purple, others white with a glitter upon them, 
as if frosted with silver. Their homes are very 
various. Some like the fresh, deep sea-water, 
while they avoid the dash and tumult of the 
waves; and they establish themselves in the de- 
pressions on some low ledge of rocks running 
far out from the shore, and yet left bare for 
an hour or two, when the tide is out. In such 
