58 Part second. 



have made by boat the beautiful trip from Amalfi to Scaricatoio will 

 have had ample opportunity of seeing the orange belt it forms on the 

 rocks immediately below the water-line. Similar corals form the large 

 reefs which are met with in the southern seas (even as far north as the 

 Red Sea) stretching often for miles, and several fathoms deep. Their 

 colouring is most exquisite. 



Closely allied to Astroides is Dendrophyllia (Fig. 109), the ske- 

 leton of which consists of pure white carbonate of lime and forms large 

 branches. The polypes are of the colour of sulphur and exhibit in the 

 expanded condition a fine ring of tentacles. This form is fairly common 

 on the coral banks of the Bay of Naples. 



The branching of the corals takes place by means of the two me- 

 thods of reproduction termed "fission" and "budding" respectively. In 

 the case of fission one organism splits into two or more parts, each of 

 which will develop into a complete individual. This process has often 

 been observed to take place ; it has also been successfully brought about 

 by dividing a living animal into suitable pieces , which have then been 

 allowed to grow on and form complete polypes. A similar fission takes 

 place in the case of the Coral-polypes, but with this important diffe- 

 rence, that the fission is not complete, but both pieces remain attached at 

 some fixed point. The two individuals form calcareous coverings, which 

 of course remain united the one to the other. Repeating this fission there 

 can arise a colony of corals , and in the course of centuries those im- 

 mense coral-reefs of which mention has been made above. The second 

 and even more rapid process of reproduction is that of budding. In this 

 case the parental polype remains intact, but at one point or other of its 

 body a new growth begins, from which, as from a bud, a new individual 

 is formed', this in the case of the Corals does not separate from the first 

 individual, but remains attached to it. The whole colony is either sup- 

 ported internally or surrounded externally by the calcareous framework 

 or covering, which the individuals form themselves J when they are dead, 

 this retains the appearance of trees or bushes, or assumes other curious 

 shapes. But whatever may be their form or colour, it must always be 

 remembered that these "corals" are not the coral-animals themselves ', 

 they are only the hard, skeletal parts, which have been formed by mil- 

 lions of small polypes. Of these many hundreds of generations have 

 already died, while their offspring, the present generation, stretch out 

 their delicate tentacles like tiny feathery crowns from the pores of the 

 coral-trees. 



Of these tree -like corals we would mention first the Sea-finger 

 ("deadmen's-fingers"), Alcyonium (Fig. 108), the skeleton of which does 

 not form a united framework, but consists of numerous loose calcareous 

 spicules ; so that the animals are able to swell themselves out by taking 

 up a large amount of sea-water. 



The Sea-pen, Pennatula (Fig. 110), can also swell itself out at 

 pleasure by taking in sea-water. When not thus expanded the body is 

 flabby, and the animal to all appearance dead ; but when it has taken 

 up sea-water it becomes beautifully transparent and erect, and the leaf- 

 like lappets are studded along their upper edge with delicate polypes 



