THE DIPHYID^!. 561 



While resident on the Florida Reef we had opportunity to observe the creatures, and 

 often removed specimens to a pail of water for examination. A box with a bottom of window- 

 glass, placed on the surface of the sea, renders objects visible with great clearness. Using 

 this one day over a Physalia, we observed several small fishes swimming among its long 

 curling tentacles. Here was a discovery, and a mystery. How is it that these little fishes 

 should be exempt from harm, when it is known that the least touch of the tentacles causes 

 instant death to other fishes ? A power resides in the tentacles that these little fishes seem to 

 be exceptionally proof against. They are so near the brilliant blue color of the Physalia that 

 they seem to be a part of them. One would regard them as a natural accompaniment, so alike 

 they are in color, and so completely protected are they from harm. 



Since this discovery of so remarkable an association of animals of diverse habits, many 

 others have been made in various parts of the world. The singular power possessed by the 

 Physalia in common with many of the corals and jelly-fishes, may well be considered here. 

 For a long time, naturally since corals and jelly-fishes have attracted attention of collectors, it 

 has been observed that a sharp, unpleasant, stinging effect is produced by contact with these 

 forms. Not until a few years since was this fully understood. We have before us photo- 

 graphs taken from the tentacles of the most powerful of these "stinging" creatures, those 

 of the Physalia, just considered. On a light magnifying power the tentacles, the long, curl- 

 ing, extensible feelers, exhibit along their surfaces vast numbers of needle-point orifices, 

 raised slightly from the surrounding surface. These are called lasso cells, because the little 

 cell-shaped swellings contain each a veritable lasso-like, slender, tubular thread coiled up 

 within, which is darted out instantly when needed. The interior anatomy of these organs is 

 somewhat complicated, but it suffices us to know that the weapon thrown out is barbed, and 

 though microscopic, yet penetrates the skin even of fishes, not only causing pain, but, from 

 the deadly effects, seems to eject at the same instant a poisonous fluid. We have seen fishes 

 swim up to the tentacles of a Physalia boldly, and very quickly turn over and die. At the 

 same time, as we have seen, there are little fishes one would suppose equally vulnerable, quite 

 at home within the dread portals, moving among and around the poisonous hanging mass. 



The great power existing in the tentacles of the Physalia we may, perhaps, be allowed to 

 illustrate by a personal relation. And we may find it proper at this place to say that our 

 long residence on the Florida Reef naturally afforded opportunities for many observations of 

 habits of marine arfimals not heretofore made public. In order to render such of the true 

 value, we may be pardoned, perhaps, the frequent iise of personal pronouns. 



It was a common occurrence after the appearance of myriads of the beautiful Physalias, 

 like minature glass ships upon the ocean, that the creatures, having no power to direct their 

 course, would, after a considerable disturbance in the ocean, as after a gale, drift ashore in 

 great numbers. The moat of the fortress was a point which caught many. 



A lad of our family, indulging with others in a bath at this portion of the moat, inad- 

 vertently swam over a Physalia ; its long slimy tentacles adhered to his chest and abdomen, 

 and the shock of the millions of poisonous lassos that were thrown into his skin was such as 

 to nearly prostrate him. Some soldiers at hand rescued him from the water, otherwise he, 

 though an excellent swimmer, would have drowned. For several hours the most vigorous 

 treatment of internal stimulants #nd external topical remedies was necessary, to keep him 

 from sinking, with the vital powers wholly overcome. The treatment consisted in rubbing the 

 parts with an abundantly strong soapy-water, warm, and the internal use of whiskey. For 

 many months the marks of the tentacles were observed on his flesh, appearing like welts left 

 after a severe lashing with a whip. 



OUR last example of this order belongs to a tolerably large family termed Diphyidae, or 

 double animals, because they are formed, as it were, of two animals, one fitting inside the 

 other. Their general form is bell-shaped. In the present genus, both animals are similar, 

 and of a somewhat pyramidal shape, and have a few points round the aperture. 



The connection between . the two portions of the DIPHYES seems to be very slight, 



inasmuch as the two halves are often found separated from each other. The progress of the 

 VOL. m. n. 



