GEOGRAPHICAL DISTRIBUTION; LIFE FORM 44I 



kiaer employed for the higher plants. They only distinguished four 

 groups; perennials, pseudoperennials, annuals and casual annuals, 

 and it would require a thorough restudy of many species in order to 

 determine to which group they belong. More recently (i937) Feld- 

 mann has proposed a new scheme, based on these same criteria 

 which can be regarded as the logical elaboration of Knight and 

 Parke's classification : 



(i) Annuals 



(a) Species found throughout the year. Spores or oospores germinate 

 immediately. 



Ephemerophyceae : Cladophora. 



(b) Species found during one part of the year only. 



(i) Algae present during the rest of the year as a microscopic 

 thallus. 



ECLIPSIOPHYCEAE : (a) with prothallus, Sporochnus. 



(b) with plethysmothallus, Aspero- 

 coccus. 

 (ii) Algae passing the unfavourable season in a resting stage. 

 Hypnophyceae — Resting stage: 



(a) spores, Spongomorpha lanosa. 



(b) oospores, Vaucheria. 



(c) hormogones, Rivularia, 



{d) akinetes, Ulothrix pseudoflacca. 



le) spores germinate and then become quiescent, 



Dudresnaya. 

 (/) protonema, Porphyra. 



(2) Perennials 



(a) Frond entire throughout year. 



(i) Frond erect. Phanerophyceae : Codium tomentosum. 

 (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 disc, Cladostephus, 

 {b) basal portion composed of creeping filaments, 

 Acetabularia. 



2 F 



