CMorophycece 55 



Richter 1 and Comere 2 have conducted experiments with a view 

 to ascertaining if certain of the freshwater Algse, especially Chloro- 

 phyceae, 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 Alga? with a robust structure and 

 Avith large chloroplasts can successfully withstand immersion in 

 salt water. Some species of (Edogonium and Cladophora can 

 live in Avater 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 Avater than Stichococcus or Tetraspora. 

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

 size and Avhen the concentration was high malformation of the cells 

 invariably occurred. Starch at first disappeared from the cells, 

 but reappeared Avhen the adaptation Avas more complete. Not- 

 withstanding the somewhat contradictory nature of these two sets 

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

 phycere can adapt themselves to an increasing salinity of the 

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

 of the green Algge to a life in hot water 3 . 



The class Chlorophycese can be conveniently subdivided into 

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

 Islands. 



Order I. (Edogoniales. Thallus filamentous, simple or 

 branched. Cells uninucleate, Avith a large, parietal, 

 anastomosing chloroplast containing one or several 

 pyrenoids. Cell-division characterized by the inter- 

 calation of a neAv piece of cell-Avail between the 

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

 Sexual reproduction by heterogamous gametes. 

 Zoogonidia Avith an anterior circle of cilia. Ex- 

 clusively freshAvater. 



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

 Lagerh. are parasites on the leaves of species of Arisarum, Philodendrum and Alo<;mi<i 

 in Ecuador (vide Lagerheini in Nuova Notarisia, 1892, pp. 120124). Trichtiphiln* 

 Weber is a genus of Algae parasitic on the hairs of Brady pus (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. 514 517. 



1 Eichter in Flora, Ixxv, 1892. 



2 J. Cornere in Nuova Notarisia, xiv, 1903, pp. 1821. 



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



