Chlorophycew 55 



Richter 1 and Comere 2 have conducted experiments with a view 

 to ascertaining if certain of the freshwater Alga?, especially Chloro- 

 phycea?, can exist in salt water. Richter states that the lower the 

 organization of the Alga the better its power of adaptation, but 

 Comere finds that only those Algae with a robust structure and 

 with large chloroplasts can successfully withstand immersion in 

 salt water. Some species of (Edogonium and Cladophora can 

 live in water containing 3'5 / of sodium chloride, Vaucheria 

 sessilis in water containing 2 / , and some of the large species of 

 Spirogyra in water containing from T8 2/ - Richter affirms 

 that (Edogonium, Spirogyra, or Vaucheria have less power of 

 adaptation to life in salt water than Stichococcus or Tetraspora. 

 In all cases the salinity of the water caused the cells to increase in 

 size and when the concentration was high malformation of the cells 

 invariably occurred. Starch at first disappeared from the cells, 

 but reappeared when the adaptation was more complete. Not- 

 withstanding the somewhat contradictory nature of these two sets 

 of experiments, it appears that certain of the freshwater Chloro- 

 phycea? can adapt themselves to an increasing salinity of the 

 water in a manner comparable with the adaptation of a few forms 

 of the green Alga? to a life in hot water 3 . 



The class Chlorophycese can be conveniently subdivided into 

 nine orders, all of which are found abundantly in the British 

 Islands. 



Order I. (Edogoniales. Thallus filamentous, simple or 

 branched. Cells uninucleate, with a large, parietal? 

 anastomosing chloroplast containing one or several 

 pyrenoids. Cell-division characterized by the inter- 

 calation of a new piece of cell-wall between the 

 mother-cell and the distal end of the daughter-cell. 

 Sexual reproduction by heterogamous gametes. 

 Zoogonidia with an anterior circle of cilia. Ex- 

 clusively freshwater. 



south of France; P. maximus Lagerh., P. Philodendri Lagerh. and P. Alocasite 

 Lagerh. are parasites on the leaves of species of Arisarum, Philodendrum and Alocasia 

 in Ecuador (vide Lagerheim in Nuova Notarisia, 1892, pp. 120 124). Trichophilus 

 Weber is a genus of Algae parasitic on the hairs of Bradypus (the Three-toed Sloth) ; 

 another species has also been found on species of Nenia (Clausilia) ; cf. Lagerheim 

 in Bericht. der Deutsch. Bot. Gesellsch. 1892, Bd x, Heft 8, pp. 514517. 



1 Kichter in Flora, Ixxv, 1892. 



2 J. Comere in Nuova Notarisia, xiv, 1903, pp. 18 21. 



3 G. S. West in Journ. Bot. July, 1902, pp. 242243. 



