radiating pseudopodia, but have an axial filament always present in each, and lack the central capsule; and are, for the most part, fresh-water forms. Finally, the PROTEOMYXA forms a sort of lumber-room for beings which are intermediate between the Heliozoa, Rhizopoda, and Flagellata, usually passing through an amoeboid stage, and for the most part reproducing by brood-formation. Zoospores that possess flagella are certainly known to occur in some forms of Foraminifera, Rhizopoda, Heliozoa, and Radiolaria, though not by any means in all of each group.[63] A. Pseudopodia the principal means of locomotion and feeding; {50} flagella absent or transitory I. SARCODINA (1) Plastogamy only leading to an increase in size, never to the formation of "fructifications." (_a_) Pseudopodia never freely coalescing into a network nor fine to the base RHIZOPODA. (*) Ectoplasm clear, free from granules; pseudopodia, usually blunt RHIZOPODA LOBOSA (**) Ectoplasm finely granular; pseudopodia slender, branching, but not forming a network, passing into the body by basal dilatation RHIZOPODA FILOSA (_b_) Pseudopodia branching freely and coalescing to form networks; ectoplasm granular; test usually calcareous or sandy FORAMINIFERA (_c_) Pseudopodia fine to the very base; radiating, rarely coalescing. (i.) Pseudopodia with a central filament HELIOZOA (ii.) Pseudopodia without a central filament. (*) Body divided into a central and a peripheral part by a "central capsule" RADIOLARIA (**) Body without a central capsule PROTEOMYXA (2) Cells aggregating or fusing into plasmodia before forming a complex "fructification" MYCETOZOA B. Cells usually moving by "euglenoid" wriggling or by excretion of a trail of viscid matter; reproduction by alternating modes of brood-formation, rarely by Spencerian fission II. SPOROZOA C. Flagella (rarely numerous) the chief or only means of motion and feeding III. FLAGELLATA D. Cilia the chief organs of motion, in the young state at least; nuclei of two kinds IV. INFUSORIA {51}CHAPTER III PROTOZOA (_CONTINUED_): SARCODINA I. SARCODINA.