112 
its lower aperture by a sphincter muscle. At the upper exterior part of the 
stomach were some brown granular bodies, which probably discharged the 
functions of the liver, and the food was completely, but very slowly, 
digested in the stomach, without passing into the somatic cavity. 
The position and function of the mesenteries were then described ; the 
primary mesenteries were partitions which connected the body-wall 
with the stomach, while the secondary and tertiary mesenteries had no 
attachment to the stomach; on the faces of these mesenteries, the repro- 
ductive organs were developed as follows : — two thin layers of the perito- 
neal membrane which surrounded the mesenteries were produced beyond 
their free edges to form the sac-like covering, within which the spermatozoa, 
or ova, when mature, burst through into the general cavity of the body. 
It was supposed that impregnation took place when both spermatozoa and 
ova were freely swimming in water, although occasionally the development 
of the young polype advanced considerably before it quitted its parent. 
The free-swimming germ was ciliated, and oblong-ovate in form, and at one 
extremity a depression, ultimately to form the mouth, was noticed ; the 
tegumentary system became by degrees distinct, thread-cells, pigment 
spots, &c, presented themselves, as well as the muscular structure and the 
tentacles. Lastly, the cilia were thrown off, and the base underwent a 
change, according to the habits of the adult animal. Besides the repro- 
ductive apparatus, there was developed in the perigastric cavity a large 
quantity of a cord-like organ, called the "craspedum," which consisted 
almost wholly of cnidse or thread-cells, and in addition to the craspeda, 
other organs of similar structure, termed " acontia," were occasionally met 
with. Only one observer had ever seen any nervous system in the Actinozoa 
and by some its existence was altogether denied. The cnidee, or thread- 
cells, diffused throughout the body, and collected in certain organs into 
large quantities, were then noticed. Each cnida consisted of a minute sac, 
formed of two walls, within which was coiled up a thread of extreme tenuity 
and great length, called an " ecthoraeum," provided with barbs, which was 
capable of being darted forth ; the interior of the sac was filled up with a 
fluid, probably poisonous. The paper was concluded by a very brief notice 
of the reparative powers of the Actiniae, which were considerable. 
The Vice-President thought that a very good future was in store for 
the Naturalists' Society, when junior members read such excellent papers, 
and enquired who were the chief writers on the subject. 
Mr. Carpenter replied, Messrs. P. H. Gosse, G. H. K. Lewis, and 
Professors Huxley and J. II. Greene. 
Mr. H. K.Jordan, F.G.S., remarked that the reproductive organs of 
the Actinozoa resembled those of certain Mollusca. The marine Gastero- 
poda were monoecious, but the land Gasteropoda were dioecious, though 
there was reason to believe that, as in the case of the Actinias, individuals 
occasionally changed their sex. 
The lateness of the hour precluded any further discussion of this paper. 
