60 Part second. 



about 60,000 pounds a year, valued at two million francs. There is also 

 a coral bed between Naples and Capri , and from it the specimens 

 in the Aquarium are obtained. The apparatus for coral-fishing- consists 

 of a cross made of heavy wooden beams , to which are attached pieces 

 of old nets, untwisted rope ends and other such material ; the whole is 

 dragged by means of a strong- rope over the bottom of the sea. The 

 branching- corals are entangled in the nets and ropes, break off and are 

 pulled up with them. To use the corals, the « bark » with the polypes is 

 brushed off and the outermost layer of the skeleton filed away ; after- 

 wards it is g-round with emery-powder and oil, and finally polished Avith 

 steel. The beads are turned and pierced on a lathe, figures are cut out 

 withg-raving'-tools. The value of corals varies already g-reatly, even before 

 they are worked. The thicker roots are often perforated by boring- animals 

 (worms and sponges) and fetch between 5 and 20 frs. per kilogramme. 

 Good ordinary pieces are sold at 40—70 frs. and choice, salmon-coloured 

 pieces 400 — 500 frs. and even more. 



In the Aquarium the Red Coral, inhabiting usually deeper waters , 

 does not last long and is therefore generally not seen in a living- condi- 

 tion. A specimen will be found enclosed in a small g-lass at the bottom 

 of tank 21. 



MEDliS.^ or JELLY FISH. 



Those who come from northern seas and remember to have found 

 on the sands ugly and oftensive masses of jelly, will find it difficult to 

 associate these with the large Rhlzostoma (Fig. 80) and Cotylorhiza 

 (Fig. 79), or with the smaller Pelagia (Fig. 81), Tima (Fig. 82), Olindias 

 (Fig. 84), Carmarina (Fig. 83) etc. ; the living Medusae have a very 

 different appearance indeed. Tlieir almost complete transparency, the 

 beauty of their movements, and often their brilliant colouring, make them 

 very attractive objects. As they swim, they take the form of a mushroom 

 or an open umbrella , the regular opening- and closing of the umbrella 

 driving them along. Round its edge are situated the sense-organs , 

 probably of seeing aiid hearing. 



From the centre of the under surface of the umbrella hangs a long, 

 generally hollow, gelatinous stalk, also transparent; it is provided at the 

 end with an aperture, the mouth. In some jelly-fish, however, the stalk 

 is short and divided into a number of small lappets , each of which 

 bears a mouth leading into a common cavity , the stomach. From the 

 edge of the umbrella hang down long tentacles, Avhich the animal can 

 at will contract and elongate to a considerable extent. These tentacles 

 are provided with numerous stinging-cells, such as have been described 

 in the case of the Actinise ( see p. 56 ) ; and , as there , they afford an 

 efficient means of defence for the delicate body. The unpleasant stings 

 experienced occasionally in sea-bathing are generally due to contact with 

 these jelly-fish. Some species , indeed , which attain a size of one to 

 two feet and a weight of 50 to 60 pounds, can sting very seriously. 



A few species shine at night with a greenish light; thus Pelagia 

 has received the specific uame of noctiluca (« night-lantern »; not to be 



