40 CORALS AND CORAL ISLANDS. 
of a septum, mesenteric in character, at or near the outer mar- 
gin. They have the aspect of a pulpy mass, or look like clus- 
ters of ovules. The ova have no chance for escape except 
through the stomach and mouth. They are covered with vi- 
bratile cilia, and rove about free for a while. As the develop- 
ment of the embryo goes forward, a depression begins at one 
end, which deepens and becomes a stomach, with the entrance 
to itas a mouth. Concurrently, septa grow out from the inner 
wall, and a few tentacles commence to rise around the mouth. 
Not unfrequently, the young has already some of its tentacles 
before it leaves the parent. There is at first but a single row 
of tentacles; the number increases with the size until the full 
adult limit is reached, the newer series being successively the 
outer. 
In the budding process, which is of rare occurrence, Acti- 
niz grow young ones on their sides near the margin of the 
base. A protuberance begins to rise and soon shows a mouth, 
and then becomes surrounded by tentacles; and, thus begun, 
the new Actinia continues to grow, usually until its tentacles 
have doubled their number, when finally it separates from the 
parent, an independent animal. At times, as Prof. H. James 
Clark has observed, small pieces of the base of an Actinia sep- 
arate by a natural process before a trace of a tentacle has ap- 
peared, and in this case ‘‘ they do not at first show any signs 
of activity, but on the contrary, remain for a long time in a 
quiet state, having the appearance of artificially separated 
pieces, seeming to be undergoing, as in the latter, a recupera- 
tive process after the shock of a separation.” After a while 
they commence to develop and grow into perfect individuals. 
Prof. Verrill mentions the case of an Actinia from Puget’s 
Sound (the Hpzactis prolifera, V.) which had three rows of 
young individuals attached to it around the middle of its 
