Organisms Consisting of One Cell 



255 



dition of this protist is not merely a stage in tlie life history of 

 the organism. No nni-nncleate stage occnrs and the ereature is 

 typically organized on the biniieleate plan. It slionld he noted 

 that the two nuclei are alike mor])liologically and presumably 

 physiologically, so they do not correspond to the macro- and 

 micro-nuclei of some ciliates. The animal may consequently be 



anfchios 



nuc 



cory.halor 



caryr - 



post, pet-isl": - 



par. It,- - 



tri. halo.- - 



ox.- 



Ah 



postbas. ^r. 



an+.'halo 



l.bltph. 

 • • -CGn-f. 



-lat. bos.^r'. 



- in^racx^ t posl. laf. 

 -anf.lat.fl. 



posi-. la^. f 1. 



FIGURE 9. GIARDIA MURIS ( AFTER KOFOID AXI) CHRISTIANSEN). 



ant. chiasnia, anterior ehiasina. ant.halo., anterior halo. ant. lat. fl., 

 anterior lateral flafielluin. ant.perist., anterior peristome, ax., axo- 

 stvle. cary., karvosoinc. eary.halo, karyosoinal halo, cent., eentro- 

 some, cyt., eytostome. fr.vent.fl., free ventral flagellum. intraeyt.- 

 lat.fl., intracytoplasmic part of the postero-Iateral flagelluni. intra- 

 nue.rliiz., intraniielear rhi/>o])Iast. lat.bas.ur., lateral basal f>raniilc. 

 post.fl., posterior flagelluni. ])Ost.lat.fl., ])osteri()r lateral tlagelliini. 

 post.perist., posterior peristome. l.l)le})h., left blepharoplast. rliiz., 

 rhizoplast. tri.halo., triangular halo. 



justly regarded, as Kofoid and Christiansen remark, as the 

 "simplest (from the standpoint of numbers only) possible nuilti- 

 nuclear organisms." "* Special notice should also be taken of the 

 blepharoplasts (1. bleph.), the a.rosiyle (ax.) and the parabasal 

 bodies (par. b.) 



Worthy of mention is the fact that this system of organs, 

 called by the authors the neuromotor system, is so well ditferen- 

 tiated from the rest of the body substance, and so permanent 



