Chapter X 

 PHYLUM PROTOPLASTA 



Phylum 6. PROTOPLASTA Haeckel 



Stdmme Protoplasta and Myxomycetes Haeckel Gen. Morph. 2: xxiv, xxvi 



(1866). 

 Subphylum Plasmodroma Doflein Protozoen 13 (1901), in part. 

 Subphylum Rhizoflagellata Grasse Traite Zool. 1, fasc. 1: 133 (1952), not order 



Rhizoflagellata Kent (1880). 

 Further names for the myxomycetes as a phylum are cited below under class 

 Mycetozoa. 



Organisms without photosynthetic pigments, mostly with flagellate stages, the 

 flagella simple or acroneme, not paired and equal nor solitary and posterior; com- 

 monly occurring also in amoeboid stages. By Haeckel's original publication, the type 

 or standard is Amoeba, i.e., Amiba diffluens. 



Amoeboid organisms are those whose protoplasts lack walls or shells, or are only 

 incompletely covered by them, and which thrust forth temporary bodies of proto- 

 plasm, called pseudopodia, functional in motion and in predatory nutrition. Pseudo- 

 podia are of several types. If massive and blunt they are lobopodia. If fine and 

 straight, not anastomosing and usually not branching, they are filopodia; or, if they 

 contain inner filaments, axopodia. If fine, branching, and anastomosing, they are 

 rhizopodia. 



The characters of the pseudopodia distinguish the accepted primary groups of 

 amoeboid organisms. Variations in this character tend to run parallel to variations 

 in the structure and composition of shells and skeletons: to a considerable extent, 

 the accepted groups appear natural. This applies to the second, third, and fourth 

 among the classes treated below. The phylum, on the other hand, is acknowledgedly 

 artificial. Some of its groups appear to have had their origins (presumably more 

 origins than one) among the chrysomonads; others are of unguessed origin. 



1. Flagellate in the vegetative condition Class 1. Zoomastigoda. 



1. Amoeboid in the vegetative condition. 



2. Producing rhizopodia; with shells, these 



usually calcareous Class 3. Rhizopoda. 



2. Producing filopodia or axopodia; mostly 



with skeletons, these usually siliceous Class 4. Heliozoa. 



2. Producing lobopodia. 



3. Producing flagellate reproductive 



cells; mostly macroscopic, subaerial Class 2. Mycetozoa. 



3. Not as above; without flagellate 



stages Glass 5. Sarkodina. 



Class 1 . ZOOMASTIGODA Calkins 



Subclass Zoomastigina Doflein Lehrb. Prot. ed. 4: 462 (1916). 

 Class Zoomastigoda Calkins Biol. Prot. 285 (1926). 

 Class Zooflagellata Grasse Traite Zool. 1, fasc. 1: 574 (1952). 

 Class Zoomastigophorea Hall Protozoology 170 (1953). 



