GENERAL PHYSIOLOGY 201 



a crown of tentacle-like pseudopodia, which hke axopodia bear an 

 axial filament (Pascher). These pseudopodia serve to capture 

 larger food bodies, while bacteria are caught in the plastic, flowing 

 protoplasm surrounding the axial filament. Somewhat similar 

 forms are found in the genera Palatinella of Lauterborn and Pedin- 

 ella of Wysotzki (Fig. 94). An interesting case of parasitism on 

 the part of green chlorophyll-bearing flagellates, Euglenomorpha 

 hegneri, has been described by Hegner (1923). The flagellates are 

 found in the intestine, and particularly in the rectum of tadpoles 

 of frogs and toads. Their inability to live outside of this habitat 

 indicates a combination of autotrophic and saprozoic nutrition. 



The number and variety of these adaptations for heterotrophic 

 nutrition in addition to the autotrophic and apparently primary 

 nutrition, lend considerable support to Pascher 's theory that the 

 colorless flagellates and possibly other Protozoa as well have been 

 derived from chlorophyll-bearing forms (see Pascher, 1916), or to 

 Victor Franz's (1919) view that all Protozoa have been derived 

 from many-celled plant types. 



2. Products of Assimilation.— These usually appear in the form of 

 storage granules of one type or other, and are dependent upon the 

 mode of nutrition and the kind of food used. In holophytic forms 

 the products are by no means always the same, but they appear to 

 be more or less characteristic for the different groups. Thus in 

 Chrysomonadida leucosin granules are the most typical, while fats 

 and oils are widely distributed (see supra); in Cryptomonadida 

 paramylum and other starch-like carbohydrates are characteristic 

 while starch grains are present in the higher types. In Euglenida 

 the characteristic products are paramylum, and in Phytomonadida, 

 true starch. 



With the majority of forms the products of assimilation vary with 

 the type of food used and are frequently so abundant in the cell as 

 to give a characteristic appearance or color to the animal. Thus 

 the refringent granules of Pelomy.ra palustris (Stol?) produce a 

 peculiar refringent effect. The brown granules of Plasmodium 

 species, characteristic of malaria, are products of hemoglobin assimi- 

 lation. Similarly the coccidin of Coccidia; peridinin of Dino- 

 flagellida; stentorin of Stentor cwruleus and FollicuUiia ampidla; the 

 pink of Hulosticha; the lavender of Blepharisma undidans or the 

 red of Mesodinium nibnim, are examples of the great variety of 

 colored cellular substances dependent upon the food that is eaten. 

 In the absence of the specific kinds of food which yield these chromic 

 products the organisms are colorless, and colored or colorless indi- 

 viduals of the same species may appear in the same culture. 



