CHAPTER LII 

 GENERAL TECHNIQUES FOR CLASSES OF PLANTS 



ALG^ 



See also Protozoa §§ 1108-1165. 



1376. Collection of fresh-water forms should be made into 

 small wide-mouthed tubes or bottles. Three-quarters fill the tube 

 with water and put only a little of the alga in the tube. 



Wettstein {Oesterr. Bot. Zeits., Ixx, 1921, p. 23) collects into a 

 culture medium. He describes two, one of mineral nutrients alone, 

 the other having a peat decoction in addition. Agar, not over 

 1 per cent., is added so that the medium does not solidify. Take 

 the medium into the field in bottles and place in it the material 

 collected. Later pour the jelly into plates. The algae develop into 

 colonies, which can be transferred to other plates. It is often 

 difficult to separate them from bacteria, but for most purposes 

 this is unnecessary. 



For methods of collection of plankton, see West and West, 

 Proc. Roy. Soc. B., Ixxxi, 1909, p. 165 ; Sutherland, Journ. EcoL, 

 i, 1913, p. 166 ; Bachmann, Biol Centrbl, xx, 1900, p. 386 ; 

 LoHMANN, Int. Rev. Hydrobiol. u. Hydrogr., iv, 1911, p. 1 ; 

 ScouRFiELD, J. Queckett Micr. Club, xi, 1912, p. 243. 



1377. Culture. Whenever possible algae should be kept alive 

 and examined in the living state. 



KuFFERATH {Rev. Algol., iv, 1929, p. 127) has a general treatise 

 on the culture of algae, citing and describing the methods of various 

 authors, including formulae and isolation technique. 



Klebs {Die Bedingungen der Fortpflanzmig bei einigen Algen u. 

 Pilzen., Jena, 1896, p. 8) used Knop's nutrient solution (4 parts 

 calcium nitrate and 1 part each of magnesium sulphate, potas- 

 sium nitrate and potassium phosphate, used in a dilution of 0-2 to 

 0-5 per cent.) for fresh-water forms. Bristol {Ann. Bot., xxxiv, 

 1920, p. 35) used 1 grm. potassium dihydrogen phosphate, 1 grm. 

 sodium nitrate, 0-3 grm. magnesium sulphate, 0-1 grm. calcium 

 chloride, 0-1 grm. sodium chloride, a trace of iron chloride, 1,000 

 c.c. distilled water. Generally a suitable formula must be devised 

 for each alga by a trial. 



See also : Cunningham, J. Elisha Mitchell Sci. Sac., xxxvi., 1921, 

 p. 123, and xxxix., 1923, p. 10 (diatoms) ; Nieuwland, Midland 

 Naturalist, i., 1909, p. 85; Kufferath, ^nn. Biol. Lacustre, ix., 1919, 

 p. 1 ; Oehler, Arch. Protistenk, xl., 1919, p. 16, and xlix., 1924, 



693 



