108 
THE OCEAN WORLD. 
but one life and one plan of development in the ■whole mass, and th lS 
depends, not on the Polypi, which are hut secondary, and oit e ® 
deciduous parts, but on the general fleshy substance of the body! 
“ the ramifications,” says Dr. Johnston, “being disposed in a variety ® 
elegant plant-like forms. The stem and branches are alike in texture- 
slender, homy, fistular, and almost always jointed at short and regul fll 
intervals, the joint being a mere break in the continuity of the sheath’ 
without any character of a proper hinge, and formed by regular period' 
ical interruptions in the growth of the polypidoms. Along the sid eS 
of these, or at their extremities, we find the denticles or cup-like cell’ 
of the polypes arranged in a determinate order, either sessile or ele- 
vated on a stalk.” Near the base of each of these there is a parti tD® 
or diaphragm, on which the body of the polype rests, with a plain ° r 
tubulous perforation in the centre, through which the connect ^’ 11 
between the individual polype and the common medullary pulp is re- 
tained. Besides the cells, there are found at certain seasons a larg er 
sort of vesicle, readily distinguished from the others by their siz 6 
and the irregularity of their distribution, which are destined fc0 
contain and maturate the ovules. 
With these animals the digestive tube is very simple, and present 3 
only one distinct orifice ; the same opening serving at once for re- 
ceiving the food and the expulsion of the residuum of digestion. Tl llS 
is one of Dame Nature’s economies, which it is not for us to dispute ' 
we must record it without further remark. 
In nearly all the Polypes the sexes are separate ; the generation 13 
sometimes sexual ; but these beings multiply also by what the zoolo- 
gists call gemmation, or buds. They are provided with organs of 
senses ; nearly all of them have eyes — an immense progress in organ- 
ization as compared with the animals which have hitherto engaged o & 
attention. Their respiration is effected by the skin — another instant 
of the economy of Nature. The apparatus of their circulation is indi 8 ' 
tinct, but they have a nourishing fluid analogous to the blood 111 
vertebrated animals. Vibratile cells and stinging hairs often c°^ et 
the entire surface of the Polypi. 
These general remarks may appear obscure and insufficient to tu 8 
larger number of our readers. They are necessarily so; they 
generalities upon animals very little known, even to naturalists. ^ e 
* “ Outlines of Comparative Anatomy." 
