LIFE FORM 373 



(2) PERENNIALS 



(a) Frond entire throughout year. 



(i) Frond erect. Phanerophyceae : Codium. 

 (ii) Frond a crust. Chamaephyceae : Hildenbrandtia. 



(b) Only a portion of the frond persisting the whole year. 



(i) Part of the erect frond disappears. Hemiphanerophyceae : Cystoseira. 

 (ii) Basal portion of thallus persists. 



Hemicryptophyceae : 



{a) basal portion a disk, Cladostephus. 

 (b) basal portion composed of creeping fila- 

 ments, Acetabularia. 



This scheme must be regarded as a great advance on the other 

 classifications, but at the same time it does not seem to take 

 adequate account of the effect of environment and, furthermore, it 

 is primarily of use for the marine algae and does not take into 

 consideration the numerous fresh-water and terrestrial species. 



Cedergren (1939) has recently published a life form scheme 

 based primarily upon the nature of the medium and secondarily 

 upon the nature of the substrate. This scheme can be considered as 

 excellent in so far as it classifies the algae in a more general sense. 



Series A. Air-loving Algae. 



(i) Terricolae (on the earth). (4) {a) Epiphytes. 



(2) {a) Saxicolae (on stone). {b) Endophytes. 



{h) Calcicolae (on chalk). (5) Epizoic forms (on animals). 



(3) Lignicolae (on wood). (6) Succicolae (gelatinous). 



Series B. Soil Algae (in the earth). 



Series C. Water Algae. 



(i) Nereider (river and stream (4) {a) Epizoic forms, 

 algae). {h) Endozoic forms. 



(2) Limnaeider (lake algae). (5) Plankton (small floating algae). 



(3) {a) Epiphytes. (6) Pleuston (large floating algae). 

 \b) Endophytes. (7) Neuston. 



Of all those so far published, however, Feldmann's appears to be 

 the most workable. The real test will come if and when it is em- 

 ployed to give biological spectra, and if the spectra from different 

 locahties e.g. temperate and tropical regions, show a distinct 



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