CHAPTER V 



PROTOZOA {COXTIXUED) : FLAGELLATA 



III. Flagellata. 



FliOTOZOA moving (andfeedimj in holozuic forms) /;?/ long Jiafjella : 

 Ijseudopodia lohen developed usucdly transitory : nucleus single or if 

 multiple not hiform : reproduction occurri^ig in the active state and 

 usucdly hy longitudinal fissio7i, sometimes alternating ivith hrood- 

 formation in the cyst or more rarely in the active state : form 

 usucdly definite: a firm pellicle or distinct cell-wall often present. 

 The Flagellates thus defined correspond to Blitschli's group of 

 the Mastigophora. The lowest and simplest forms, often loosely 

 called "Monads," are only distinguishable from Sarcodina (especially 

 Proteomyxa) and Sporozoa by the above characters : their 

 artificial nature is obvious when we remember tliat many of the 

 Sarcodina have a flagellate stage, and that the sperms of bisexual 

 Sporozoa are flagellate (as are indeed those of all Metazoa except 

 Xematodes and most Crustacea). Even as thus limited tlie group 

 is of enormous extent, and passes into the Chytridieae and 

 Phycomycetes Zoosporeae on the one hand, and by its holophytic 

 colonial members into the Algae, on the other.^ 



Classification. 



A. Fission usually li)Ugitudiiial (transverse only in a cyst), or if nuiltipk', 

 radial and comjilete : ])Ldlicle aljsent, thin, or if armour-like, with not 

 more than two valves. 



I. Food taken in at any part of the ))ody liy pseudo2)odia 



1. Pantosto.mata 

 Midticilia Cienk. ; Mastiyamoeba F. E. Sch. (Fig. 37, 4 . 



' The alleged niicrouucleus of certain forms appears to be merely a "blcpharo- 

 plast '' (sec p. 19) ; even when of nuclear origin, as in Trypanosomo, it has no 

 fuiirtion in reproduction like the microuucleus of Infusoria (sec pp. 115, 120 f. ). 



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