416 



within the clutches of the merciless polyp. The hydra produces 

 young by budding, and does not seem to object to being turned 

 inside out or cut into pieces. Should these remarks on a fresh 

 water creature have seemed like a digression, it will now be seen 

 that they are not really so, because the hydra is the type of a very 

 large number of marine polyps, to which the term liydroids is 

 applied. They are like the hydra itself, hollow-bodied animals 

 belonging to the great sub -kingdom called Cselenterata, which is 

 wide enough to take in such interestmg creatures as the jelly fish, 

 the sea anemone, and the coral building polyp. Those whitish 

 branched plant-like things that are found on the beach in such 

 plenty, and are so commonly called seaweeds, are zoophytes or 

 colonies of liyroid animals. Thousands of the tiny animals, polyp- 

 ites as they are called, often inhabit a single polypidom, each 

 animal being lodged in a hydrotheca, and all the members of the 

 colony being organically united through the common flesh that 

 runs down the stem. It is by budding — much as plants bud — that 

 the colony is built up from a smgle animal, and, of course, the 

 polypidom itself is formed by the united work of the animals them- 

 selves. The tentacles of the hydroid animal are furnished with 

 thread cells and darts, like those of the hydra itself. Sertularia 

 abietina, a deep-water species (specimen), is very commonly seen 

 (Hincks, vol I., 266; vol. II., p, 55) growing on the shell of the 

 common scallop. Fine specimens are as much as a foot high, and 

 branched bipinnately, are very handsome. Each little polypite has 

 the mouth furnished with about 26 or 30 tentacles. 



Hydra-like animals are very numerous, and are divided into many 

 genera, to only one of which— /uiukna — jour attention is asked 

 for a minute or two. Tubularia indivisa (specimen) grows on our 

 rocks, and is most likely plentiful here and there, The colony is 

 made up of a number of simple stems, often twisted and interwoven 

 at the base. Each stem has a thread of flesh running down to the 

 root, and is crowned with a deep red polypite, of the beauty of 

 which words cannot give any proper idea. The writer, who has 

 seen this lovely animal-plant, with the plate-like tentacles spread 

 out, would fain dwell upon its charms, but time forbids, and it may 

 be that we do uot all see with the same eyes. However, let the 

 coloured plant tell its own tale, Professor Allman, in the work 

 now before you, lias described and beautifully figured the Tubularian 

 Hydroids, 



Wonderful creatures are the well-known jelly fish or sea nettles 

 — the medusae of naturalists. In Cuvier's Animal Kingdom they are 

 called Acalephse, on account of the stinging and smarting that is 

 caused by contact with them. Certainly they are not quite bad 

 enough in their tastes and dispositions to be fairly named afte^ 



