CHAPTER III 



PROTOZOA {(JOXTIXUED) : SARCODIisA 



I. Sarcodina. 



Protozoa jjcrformi^ir/ most of their life-pi'ocesses hy 23seudo}3odia ; 

 nucleus freqiiently giving off fragments {chroniidia) which may 

 flay a 'part in nuclear reeonstitution on division ; sometimes with 

 hrood-cells, lohich may he at first flagellate ; hut never reproducing 

 in the flagellate state} 



1. EnizopoDA 



Sarcodina of simple form, ivhose pseudopodia never coalesce into 

 networks (1)/ nor contain cm axial fllameyit (2), which commonly 

 midtiply hy hinary fission (3), though a hrood-formation may 

 occur ; which may temporarily aggregate, or undergo temporary or 

 2)ermanent p^lastogamic union, hut never to form large plasmodia 

 or complex fructifications as a 2^Telude to spore-foi^^nation (4) ; test 

 iclien present gelatinous, chitinous, sandy, or siliceous, simple and 

 l-chamhered (5). 



Classification.^ 



1. Ectoplasm dutinct, cleai- ; iiseudoiMidia lilunt or ta]>eving, Imt not liraiicli- 

 ing at the apex ...... Lohosa 



Amoeba, Auctt. ; Pelomyxa, Greeff ; Trichosphaerium, A. Sclmeid. ; 

 JHnamoeha, Leidy; Am2)hizonella, GreeS ; Centropyxis, Stein; Arcella, 



' On this ground I have referred Paramocba, GreelT, to tlie Cryptomonadineae. 



- Dill'erences (1) from Foraminifcra ; (2) from HclUr.oa ; (3) from Protcomyxa 

 and Sporozoa ; (4) from My.vomyectcs ; (5) from many Foraminifcra. 



" I have not followed the usual classification into Gymnamoebaeand Thecamoehae, 

 according to the absence or presence of a test (perforated by one or more openings) 

 in the active state, as such a test occurs in isolated genera of Fiagellata and 

 Infusoria, and does not appear to liave any great systematic importance. 

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