EPIDERMIS OF- THALLOPHyTES. 121 



iptefrial tissue, and ciiticularise'd on the outer side, or clothed by a cuticle : and even 



' FIG. 124.— Examples of the forms of hairs. A QiPtectranth^sfrutiVJsits; B Cajophoralateritia; C Hiercueum 



pitiferttm; D CheiratUhtis^Cheiri. (After De Bary.) " . 



in organs where a single layer of cells constitutes the tissue— as in the prothallia! 

 of FernSj the leaves of Mosses, and in many AlgsSj^and where iSie vegetative body 



