“It would,” says he, “tend to the better regulation of our fisheries and to the augmentation of our food supplies, if we knew as much about the herring or the haddock as we do about the salmon.” It is well known that fish, valuable as food, are too often captured at improper seasons and in a wasteful manner. Passing on to higher forms of animal life, the polyps and acalephæ of the older authors, now classified as the _Cœlenterata_, we find creatures of a superior organisation to those lately under notice. Regarded generally, their bodies are soft and gelatinous, they possess alimentary canals and digestive apparatus, and in nearly all cases the sexes are separate, generation being sometimes sexual and sometimes by gemmation or budding. This brief introduction to the subject must be taken only in a general, not a special sense, for there are numerous exceptions to be found among the animals classified as Cœlenterata. “The sub‐kingdom Cœlenterata naturally divides itself into two groups—that of the _Hydrozoa_, and that of the _Actinozoa_. The fresh‐water hydra will serve as an example of the first, and the common sea‐anemone of the second group. The essential difference between the two is, that in the former the stomachal cavity is not separated from the general cavity of the body, and the reproductive buds are external; while in the latter the stomachal cavity is let down, as it were, as a partially‐closed sac, into the general cavity of the body, and the reproductive buds make their appearance between the walls of the general cavity of the alimentary or stomachal sac, and consequently internally. But in both there is a free communication between these two cavities—a communication obvious in the Hydrozoa, and which may be often verified in the case of the sea‐anemones, by the young anemones making their appearance at the mouth of the parent anemone, having just escaped from the general cavity out into the alimentary cavity of its body.” [Illustration: MEDUSÆ.]