98 



NATURAL SCIENCE NEWS. 



of our party, with two men, taking 

 harpoons and lines, got into the 

 dingy and started for some sharks 

 not far off. The harpoon was soon 

 thrown with telling effect. The 

 victim proved to be a porpoise in- 

 stead of a shark. They struck him 

 not more than twenty rods from 

 the schooner, but in ten minutes 

 both boat and porpoise were half 

 a mile away. There were three 

 hundred feet of line attached to 

 the harpoon, and this was let out 

 as necessity demanded. The mon- 

 ster would dive, but being an air- 

 breather was obliged to come to 

 the surface every few moments. 

 At such times they sometimes got 

 him near enough the boat to hit him 

 with an axe, but apparently with 

 little effect. Being afraid of losing 

 him, another harpoon (carrying 

 three hundred feet of line) was 

 driven into his side. Still he 

 seemed as vigorous as ever. Sig- 

 nals were made for a rifle; this was 

 sent to the scene of the conflict by 

 another small boat; and four bul 

 lets were fired into the animal. 

 But they failed to kill. For two 

 hours and a half the chase was 

 kept up. At times he went through 

 the water with terrific speed. They 

 traversed at least ten miles, and I 

 expected more than once to see 

 the boat swamped. But fate was 

 against the porpoise, His blood 

 was pouring in streams from six 

 wounds. He was evidently getting 

 weaker, and toward the last swam 

 close by the Rosebud, making for 

 the land. When a few rods from 

 shore he gave one tremendous 

 groan, and expired. A shout of 

 triumph went up from the part)'. 

 He was towed to the beach, and a 

 careful measurement showed him 

 to be nine feet four inches in cir- 

 cumference in front of the dorsal 

 fin. We estimated his weight at 

 twelve hundred pounds. The pro- 

 cess of removing the hide occupied 

 three men an hour and half. He 

 was an old male, and had lost sev- 

 eral teeth. In his stomach were a 

 dozen mullets, evidently eaten just 

 before he was struck. The hide 

 of the porpoise, elegantly mounted, 

 is now in the museum of the Chi- 

 cago Academy of Sciences, along 

 with sharks and other trophies of 

 the cruise. That night we sailed 

 for Key West. The collections of 

 the expedition were shipped home, 

 and a few days after I left by 

 steamer for New Orleans. This 

 closed my connection with the 

 Rosebud Expedition. — W. IV. Cal- 

 kins in an old issue of Science JVcws. 



Common Sponges. 



Twenty years ago, sponges were 

 sufficiently proved to be animals, 

 but have not until lately been ad- 

 mitted into the zoological classifi- 

 cations. They are now known to 

 belong to egg-bearing Metazoa, 

 though probably the simplest of 

 that grand division of animals. An 

 ordinary sheep's-wool bath-sponge, 

 which comes from our southwest- 

 ern coast, and can be bought 

 cheaply by the pound at all whole- 

 sale druggists, is recommended as 

 the most available for class teach- 

 ing. Other sponges, known to 

 the fishermen as "dead men's fing- 

 ers," can be found commonly on 

 the piles of old wharves and rocks 

 below low tide, along our north- 

 earstern coast. 



When living, the commercial 

 sponges — for there are a large var- 

 iety of Spongia known to the natur- 

 alist, which from various causes, 

 are not employed in the arts — are 

 of a dark brownish or blackish col- 

 or and resemble beef-livers, the 

 chitinous fibres of the skeleton be- 

 ing nowhere visible. The larger 

 openings of the main tubes or ca- 

 nals penetrating the mass are ap- 

 parent when the animal is undis- 

 turbed, but close when it is hand- 

 led; the smaller openings are not 

 visible, being covered by an exter- 

 nal skin which envelopes the whole 

 mass. This skin consists of two 

 layers, of which the inner also de- 

 scends into all the tubes, lining the 

 cavities throughout the body; the 

 outer layer one does not descend 

 far into the canals, and acts as a 

 sort of seive throug which the wa- 

 ter is sucked by a peculiar mechan- 

 ism into all the small chambers 

 and canals, whence it finds its way 

 into the great vertical trunks and 

 is ejected with force at the two or 

 three large orifices which are so 

 plainly to be seen in a distended 

 bath-sponge. The water thus cir- 

 culating through the interior of the 

 sponge yields up its nutriment, (a 

 minute stomach being improvised 

 out of a cell of the dense fleshy 

 mass which is supported by the 

 elastic fibrous skeleton and com- 

 prises the living substance of the 

 sponge), the instant a floating 

 morsel is captured by one of the 

 tiny threads which stud the inter- 

 ior chambers of the animal. These 

 threads are always stretching out 

 into the passing current, fishing 

 for food. The sponge, then, has 

 no permanent stomach, but ex- 

 temporizes as many as it has 

 mouthfuls, out of any portion of 



its interior surface which is con- 

 venient. When the particle of 

 food is digested, the refuse is forc- 

 ed out into the expelling canal, and 

 the quondam stomach disappears. 

 The food consists of the floating 

 clouds of minute animals and 

 plants which abound where the 

 Metazoa flourish. 



Sponges whose skeletons are of 

 a horny substance called keratode, 

 do not grow on our coast north of 

 Cape Hatteras, nor on the coast of 

 Europe north of France; their lim- 

 it in the Pacific is not percisely as- 

 certained, but does not extend far 

 north. It is to this class that the 

 commercial sponges belong. None 

 useful for domestic purposes are 

 found on our Atlantic coast north 

 of Key West; but in the Gulf they 

 occur up to Santa Rossa. Key 

 West and Nassau are the principal 

 markets. The majority of those 

 displayed in the windows of apoth- 

 ecary shops are from the Mediter- 

 ranean. In these the lighter color 

 and superior elasticity and density 

 of the skeleton are apparent. They 

 hold water better, are much softer 

 and more agreeable to the touch, 

 and far more elastic and durable 

 than the American forms, which, of 

 course, they greatly exceed in price. 

 The inferior quality of American 

 sponges is probably due to the ex- 

 cessive heat of the waters in which 

 they live, to the greater scarcity of 

 food, and to the great quantities of 

 chalky sediment beaten out from 

 the shores and reefs by the winter 

 storms of the Caribbean Sea, The 

 Red Sea sponges are not so fine as 

 the Mediterranean, but better than 

 those from our shores. Altogeth- 

 er, only three species are sold in 

 the shops, but these are divided 

 by the dealers into a great number 

 of varieties, each of which is named 

 according to locality, etc. 



Sponges grow always attached 

 to hard surfaces, coral-reefs being 

 the favorite support. They are 

 hunted for in shallow water by the 

 use of a water-glass. This is a 

 tube of thin boards or iron pipe, 

 several feet long, with a frame of 

 glass at one end, which, when sub- 

 merged, prevents the fishermen's 

 sight from being disturbed by the 

 glare of the moving surface of the 

 sea. Having discovered the sponge, 

 it is captured by the aid of a sort 

 of fork, or by divers who descend 

 either naked or in armor. 



The naked diver is carried down 

 by a broad flat stone of marble, of 

 about 25 pounds' weight, which he 

 holds at arm's length in front of 

 him, and uses to guide his descent, 

 to protect his head when he first 



