CCELENTERA TES 



posed calyx (o), eggs are seen, while the lower (/) contains a large male vesicle, a'nd 

 at its side an egg (o}. After hatching, the ciliated larvae leave the egg while still 

 within the chambered cavity of their parent (B). Two of the long worm-like larvae 

 (/>") can be seen in the illustration through the delicate body wall of a polyp 

 whose tentacles are retracted, and others are visible in a cell which has been cut 

 open. In the uppermost cell a larva (a) is seen in the act of passing out through 

 the mouth (). The red coral is found only in the Mediterranean and Adriatic seas; 

 the most noted coral fisheries being carried on off the Algerian and Tunisian coasts, 

 at depths of forty to one hundred fathoms. The coral obtained in these fisheries 

 varies greatly in value. The price of the broken pieces, often perforated by worms 

 and sponges, is from fifty cents to two dollars a pound; good coral fetches from 

 four to seven dollars, while choice thick coral, especially the rosy red kind, is bought 

 at from forty to fifty dollars a pound. Such pieces as are black, either superficially 

 or throughout their whole thickness, are sold separately at from one dollar to one 

 dollar and fifty cents a pound; these are not of a different species, but, having long 

 been covered with mud, have changed color as a result of chemical changes. The 

 coral is made into articles of ornament both in Paris and Marseilles, but the chief 

 industries are in Naples, L,eghorn, and Genoa. 



We conclude our description of these eight-rayed corals with the organ-pipe 

 corals ( Tubiporidai} , a family consisting of the one genus Tubipora, the members 

 of which are neither numerous nor varied. The individuals resemble in form, in 

 the number of their delicate tentacles and in their soft anterior body, the other 

 living members of the order. In the structure of their skeleton they are, however, 

 unique among extant corals, and recall certain extinct forms. Each individual 

 secretes a smooth-walled tube, without calcification of the vertical septa. These 

 tubes, which, like the pipes of, an organ, stand almost parallel, are united to form 

 a stock by means of transverse platforms. These latter do not, however, correspond 

 with the inner transverse partitions (tabulce}, by means of which the upper living 

 part of the tube is from time to time cut off from the dead part below. The trans- 

 verse platforms are neither regularly parallel nor continuous; nevertheless they do 

 indicate in a general way stages of growth. They are very richly provided with 

 nutritive canals, and are of special importance for the whole stock, inasmuch as the 

 young individuals bud out from their surfaces. As the longer tubes grow, the in- 

 tervals between them increase, and as soon as there is room enough for a new polyp, 

 one buds out from the platform. Division of the individuals or formation of buds 

 from the tubes themselves does not take place in this family. 



Having described a few typical corals, and explained their general 



structure and characteristics, some mention must be made of the im- 

 and Islands 



portance of these creatures in the economy of nature. Whereas most 

 forms of animal life, in passing at death into their elementary constituents, leave no 

 visible traces of their existence, the corals, or at least the numerous reef-making 

 forms, build monuments which last for hundreds of thousands of years, and may be 

 said to attain their greatest importance in the influence they exercise upon the life 

 and development of the human race. Professor Haeckel has described the magical 

 effect of a first sight of a shallow coral reef, enjoyed by him on the coasts of the 



