PH.EOPHYCE^] 



43 



parts which extorts the use of such terms as stem, 

 leaf, and root, however unconventional such an 

 employment of them may appear from the point of 

 view of formal morphology. It has been pointed out, 

 for example, that the transition from the lower to 

 the upper leaves of certain species of Sargassum 



FIG. 3. a, Coccophora Langsdorfii (reduced) ; ft, transverse section of stem ; 

 e, longit. section of same passing through base of leaf, b and c much magnified. 

 (After A. L. Smith, in Phyc. Mem.) 



furnishes a parallel appearance to the familiar 

 change of form to be observed in the leaves of 

 flowering plants. When such differentiation is 

 allied with the production of special receptacular 

 or fruiting branches, arising from the base of the 



