Physiology 447 



Eiiglenida. Further study of these flagellates should prove interesting 

 because the order includes chlorophyll-bearing species, colorless saprozoic 

 types {Astasia, Menoidium, etc.), and various holozoic genera {Hetero- 

 nema, Peranema, etc.). Furthermore, such species as Etiglena anahaejia, E. 

 deses, E. klehsii, E. pisciformis, and E. stellata have failed to grow in dark- 

 ness (105), whereas Euglena gracilis grows well under such conditions 

 (377, 460, 549). Although investigations on holozoic types are in progress, 

 previous reports are limited to Euglena and Astasia. 



Inorganic sources of nitrogen have been tested for several species of 

 Euglena (104, 105, 109, 175, 177, 189, 377, 508). The available data in- 

 dicate that ammonium salts are generally more satisfactory than nitrates. 

 However, nitrates apparently are adequate for Euglena anahaena (109). 

 Among the colorless Euglenida, Astasia longa has been maintained on 

 ammonium-N (503). 



Organic sources of nitrogen have been investigated for several species 

 of Euglena (104, 105, 549). Asparagine and various amino acids have sup- 

 ported growth of one species or another, but several species have shown 

 interesting differences in their apparent abilities to utilize particular 

 amino acids (105). Possible relations of mineral requirements and pH of 

 the basal media to the utilization of amino acids have not been investi- 

 gated adequately. 



The available information on carbon sources is based mainly on growth 

 of Euglenida in peptone media, although acetate has supported slow 

 growth of Astasia longa (503) and Euglena gracilis (504) in heteroau to- 

 trophic nutrition. A number of organic acids — including acetic, propi- 

 onic, butyric, valerianic, caproic, /^o-caproic, octylic, nonilic, lactic, and 

 pyruvic — have stimulated growth of Astasia (456, 465, 466, 467) and 

 Euglena (456, 467) in peptone medivmi. Growth of Euglena (332, 456, 

 467) and Astasia (456, 467) also is stimulated by certain alcohols, includ- 

 ing ethyl, propyl, butyl and hexanol. 



Protomastigida. Pure cultures of parasitic Protomastigida have been 

 available for many years but most investigators have been interested in 

 these flagellates as parasites rather than in their nutrition. However, the 

 investigations of Marguerite Lwoff (349, 363, 366) on several parasites of 

 insects showed that Strigomonas oncopelti grows well in peptone media 

 while certain other species have more complex requirements. 5. jasciculata, 

 from mosquitoes, requires a small amount of blood or hematin as a 

 supplement to peptone medium. Leptonionas ctenocephali, from the 

 dogflea, requires such a supplement in higher concentrations (349). Spe- 

 cific requirements of S. culicidarum include at least nine amino acids, 

 hematin, thiamine, riboflavin, pyridoxamine, trace minerals, and possibly 

 two or three additional vitamins (567). 



Certain Trypanosomidae of vertebrates require, in addition to hematin, 

 other growth-factors not supplied by peptone solutions (Table 8. 3). 



