168 



ZOOPHYTA ASTEROIDA. 



more or less compactly pressed according to the nature of the spe- 

 cies. (Fio-. 21.) The whole section presents a certain resemblance 

 to a similar section of a dicotyledonous tree : (Fig. 20.) the me- 

 dulla in position and outward appearance is a pith ; the horny 

 axis is the wood ; and the fleshy crust has been denominated the 

 bark;* — nor perhaps could fault be found with this language, 

 since it is sufficiently illustrative, had it not been the mother of 

 some very erroneous notions, and a great means of their propa- 

 gation and continuance. Thus Linnaeus, in his definition of 

 Gorgonia, calls the axis a vegetating stem ; and as if this was 

 not sufficiently explicit, we find Pallas entering into detail and 

 telling us that the concentric circles are produced by successive 

 transmutations of the fleshy crust, in the same manner that the 

 circles of the wood of trees are formed by transformations of the 

 inner layers of the bark.f And this opinion, if we may judge 

 from their language, has been adopted by many, and even re- 

 cent, authors, though Ellis had previous to its promulgation:}:, 

 Fig. 20. Fig. 21. 



and also shortly afterwards, demonstrated that there was not on- 

 ly no real resemblance, but such remarkable differences as 

 rendered the hypothesis altogether untenable. § The pith of 



* Lin. Syst. 1289. 



f Elcneli, p. 162. He seems, however, to have had his suspicions that the 

 theory was questionahle, for he adds — " Qiianquam diversissima corticis natura, 

 ejusdemque facilis a ligno separatio, siiggerere possent : hujus strata potius ex 

 depoi-ito intiis succo fieri, aut lignum, prout ossa animalium sanguineorum intra 

 periosteum, generari, augeri, durescere."' 



t Coral. 65. Lin. Corresp.. i. 225. Phil. Trans, (an. 1776) abridg. xiii. 721. 



§ What then could induce Blumenbach, so late as in 1825, to write thus?— 

 " The stems appear to be reallt/ vegetables (the woody nature of which in the 

 larger ones cnnnot be mistaken) incrusled with corals." — Man. of Nat. Hist. 

 Trans, p. '271- 



