In'TRODUC'TION. XV 



one was of an animal Nature, which ocular Demonftration 

 had already convinced me of, then the other muft be fo too. 



And, I am perfuaded, that whoever compares them to- 

 gether, and views attentively the Succeflion ot riiing Tubes, 

 that change infeniibly into Ramifications of Cells in the Ke~ 

 ratophyton^ and, at the fame time, examines the Structure 

 of that Veficulated Coralline, called the Herring-bone Co- 

 ralline, Plate X. Fig. a^ &'c. will be of my Opinion. How 

 the woody or horny Part of the Stem and Branches are form- 

 ed, feems to be the great DifHculty to the curious Enquirer 

 to account for, unlefs he is allowed to fuppofe it a Vegetable. 



But, during thefe Obfervations, I fortunately received from 

 America^ a curious Specimen of a Sea- Fan, Part of which 

 is delineated in Plate XXVI. Fig. C, 0, A ^j which plainly 

 demonflrates, that Animals of the Polype-kind are the Fa- 

 bricators both of the horny or woody, as well as the calca- 

 rious, Covering of this curious and numerous Plant-like Co- 

 lony of Infeds. 



The next Clafs, which is the Efchara^ deferves our No- 

 tice, and a nicer Scrutiny. There appears a great Probabi- 

 lity of fome of thefe being the Matrices or Ovaries of certain 

 Species of Shell-fifli, perhaps of the Bivalve Kind. 



So little Enquiry has yet been made into the Origin of 

 Shell- fifli, that we feem ftill ignorant of the Production, or 

 firft Beginning even of the moft common Sorts among us, 

 fuch as Oyfters, Cockles, and MufTels. 



Many of the Akyoiitums^ or thofe mifhapen Sea- produc- 

 tions called fo, deferve our Attention. If we could examine 

 thefe Bodies carefully, at different Seafons of the Year, I 

 do not in the leaft doubt, but they would amply reward our 

 Curiofity with a Fund of new Difcoveries, 



As 



