ZOOPHYTES. 359 



tire hills, of very old formation, extending for hundreds of 

 miles, characterized by the corals they contain, thus proving 

 that these animals also existed in countless numbers in a 

 former condition of our earth, and that then as at present, 

 they assisted materially in adding to the solid matter of the 

 globe. Zoophytes, from the simpHcity of their structure, 

 and the geognostic relations of the rocks in which they are 

 occasionally found, appear to have been called into exist- 

 ence before the other classes of animals."* 



The red coral ( Corallium rubrum\ of which are formed 

 so many beautiful ornaments of female dress, and the value 

 of which as an article of commerce is consequently great, 

 occurs abundantly along the coasts of Tunis and the shores 

 of the Red Sea. It is of comparatively slow growth, and 

 is never found in such splendid masses as the madre- 

 pores. Light effects a powerful influence on its growth. 

 ♦' Thus, at a depth of from three to ten fathoms, it grows 

 one foot in eight years ; at the depth of from ten to fifteen 

 fathoms, the same length in ten years ; at the depth of one 

 hundred fathoms, same length in twenty-five or thirty years ; 

 and at the depth of one hundred and fifty fathoms, the same 

 length in forty years. It is also remarked, that in general 

 the colour is deeper and richer in shallow than in very deep 

 water. The coral of Barbar}" is not reckoned so fine as 

 that of Italy or France."t 



The common sponge {Spongia officinalis) forms also an 

 article of traffic along some of the African shores. 



We shall conclude our sketch of African zoology by a 

 brief notice of a dangerous and disgusting animal (Filaria 

 medinensis), commonly called the Guinea worm. This 

 gigantic parasite contrives, in a way best know to itself, to 

 enter beneath the skin of the human race, especially that 

 of the legs, where it will remain for several years, attaining 

 in the mean time to the enormous length of ten feet, and to 

 the thickness of a pigeon's quill. According to the place and 

 manner of its abode, it occasions pains more or less severe ; 

 and in the more unfortunate and disastrous instances, its 

 continued presence is followed by convulsions and death. 



* Murray's Historical Account of Discoveries and Travels in Africa. 

 T0l.il. p. 471. ♦ Ibid, p. 473 



THE END. 



