the british - Corning Museum of Glass

xxii INTRODUCTION.
separate, and inclose the reproductive organ (f), uniting
again beyond it into a second mesentery (g), which is
bounded by the craspedum (h) presently to be described.
Both mesenteries are full and plaited, especially the craspedal
one.
The spermatic fluid is discharged in a turbid cloud
through the mouth, and is diffused through the surroundingwater
(pp. 99, 100). The ova are also discharged through
the mouth, or through the gonidial grooves (pp. 97, 98, 99).
The development of the egg is into an infusorium-like
germ, differing in shape in different species, but always
covered with vibratile cilia, and freely locomotive. Examples
of the occurrence of these will be found infra (passim),
and many highly interesting details have been recorded in
the magnificent works of Sir J. G. Dalyell. The manner
in which the development of the Anemone proceeds has
been illustrated by Dr. Cobbold; * a depression in the
surface of the globose embryo becomes the general cavity;
the edges then become incurved and descend into the cavity,
forming the stomach; septa spring from the inner wall,
beginning from the summit and extending downwards, and
tentacles bud from around the mouth. Eggs, germs, or
fully formed young, are discharged indifferently through
the mouth: in the latter two cases the embryos have passed
their earlier developments within the general cavity.
7. Teliferous System. In common with some nearly
allied forms the ACTINARIA are furnished with a system of
armature of most extraordinary character. It is comparatively
a recent discovery that their tissues contain excessively
minute bodies, in the form of oblong or oval transparent
vesicles, which have the power of shooting out a longthread
of extensive tenuity. Wagner first drew the attention
of physiologists to these organs, though he mistook
their functions for that of spermatozoa; an error which was
participated by Dr. Wyman, in his observations recorded in
Dana's magnificent work on Zoophytes. Their true character
has, however, been sufficiently established by many"
observers, including Wagner, Erdl, Quatrefages, Kölliker,
Agassiz, and myself. These bodies I have called cnidœ,
or thread-cells.
The cnidœ, in the Actinoïd Zoophytes, are not confined
to one organ or set of organs. They are found in various
* Annals Nat. Hist, for Feb. 1853.