GORGONIA, OR SEA-FAN. 523 



is harder than another. Now in the group at present under 

 consideration, a solidification takes place in the centre or axis 

 of the polypidom, and often in the integument also. Almost all 

 the species included in it have an arborescent form ; and so much 

 does the flexible axis of many kinds resemble the stem of a plant, 

 that, even so late as the year 1825, the celebrated Blumenbach 

 writes '* The stems appear to be really vegetables (the woody 

 nature of which in the larger ones cannot be mistaken) incrusted 

 with corals." 



1095. Among the Gorgonice, or Sea-Fans, there are some 

 species which very closely resemble the Alcyonia, in the uniform 

 distribution of the firm texture through their whole substance. 

 In others, however, a firm horny skeleton is found, which is 

 commonly known as the Sea-fan ; and, in the living state, the 

 flesh which clothes this is covered by a dense integument, con- 

 taining an abundant deposition of calcareous particles. If the 

 flesh be allowed to dry upon the stem, the integument remains 

 as a friable crust, which may easily be peeled or rubbed off, 

 disclosing the horny stem within. No mark of the habitation 

 of the Polypes is ever found upon the internal axis ; but the 

 remains of the cells may often be observed in the integument, 

 when dried over it. The dry form in which the skeleton of the 

 GorgonicB is commonly known, does not give a correct idea 

 of its real character ; since, in the living state, there is by no 

 means a complete isolation between the hard axis and the soft 

 living flesh, but the one passes gradually into the other. On 

 cutting across the stem, it is observed that it is formed by 

 concentric layers, like those of a dicotyledonous tree ; and it is 

 probable that these are formed by the successive consolidation of 

 the flesh in contact with its surface. Beyond this general 

 analogy, however, no resemblance can be made out ; since nothing 

 like the intricate arrangement of dissimilar parts in a woody 

 stem, can be found in these simply-organised but beautifully- 

 formed structures. Whilst the axis of the Gorgonia is usually 

 brown or black, its crust often exhibits colours of great brilliancy, 

 especially in the living state ; in some species it is of a deep red, 

 in others of a bright yellow, and in others of a crimson hue. 



