ZOOPHYTES. 3T7 



free communication with that of the creeping root. The 

 wall is thin, and perfectly transparent and colourless ; 

 the whiteness of the whole being dependent on a soft 

 medullary core of living jelly, which, permeates the 

 whole structure, on which the horny sheath is as it were 

 moulded. 



This medulla is pierced with a canal, through which 

 a fluid circulates, caiTying 

 along numerous minute gran- 

 ules with a quivering, jerking 

 motion ; this is doubtless the 

 nutrient fluid conveying the 

 products of digestion to every 

 part of the common structure. 



Where the branches issue 

 from the angles of the stem, 

 the medulla, and consequent- 

 ly the horny sheath, is dilated 

 into a knob ; immediately 

 above this there is a joint- 

 like consti'ictiou in the tube, 

 and the branch itself is in 

 sected by four or five such 

 constrictions, so as to form as 

 many rings. Its extremity laomedea. 



then expands into an elegant cup, or vase, of extreme 

 tenuity and transparency, shaped like a wine-glass, with 

 the rim undivided, but so thin and subtle as to be seen 

 with the greatest difficulty. 



These cups, or cells, are each the proper habitation 

 of a polype, which is nothing else but the termination 

 (in this direction) of the living, gi'owing, vascular pith. 

 The latter becomes exceedingly attenuated to pass 



