1S4 



PROTOZOA 



Sub Order I. THYTOFLAGELLATA. Planl-likc chlorophyl-bcaring 

 flaL^L'llates, mostly with eye-specks. \'ol\'OCIxa: ]'oli-o.\- i;Iobiilor* green 

 sphere 0.2-0.7 'i"""' i" iliaineter, Ceinsisting of thousands of indi\iduals. Euci.F,- 

 xid.e: Kio^lcita •:■ I r i d i /'■ dig. 1341, solitary, coloring small j>ools liv their im- 

 mense numbers. Cin-;vS(.iMOx.\Dlx.\, plant-like in nourishment: Piiiobrvcii/'' 

 Sub Order II. CI HbWOFLAOELLATA. \Vith collars; mostly small 

 colonial forms. Coiloni^a.''' Coiun-huliiim (hg. 136). Sub Order III. EUELA- 

 GELL.\TA. Animal flagellates, taking solid food bv pseudopodia or bv cvto- 

 stome. Elere lielong, besides numerous free forms, se\eral ]>arasites of man: 

 Laniblij iiilc.sliiidlis ilig. 140), also in rats and mice: TrhJioDnnnis Jioniinis in 

 small intestine. T. licili\ultoniiii (lig. 141) is similar. Numerous flagellates are 

 blood parasites, among them Trypoiosoiiia brucci, which is introduced into 

 horses and cattle in Africa by the tze-tze fly {Glossimi iiiorsilaiis), sometimes deci- 

 mating the herds. Two other species, Tr. ci'ivisii and Tr. cqiiipcrdiim attack 

 horses. Tr. (^aiubiciisc {caslcllaiii) occurs in the blood and cerebrospinal fluid of 

 man in tropical Africa, causing the 'sleeping sickness,' especially fatal to negroes, 

 intermediate host Glossiiia palpalis. Tr. Incisii (fig. 13S) in rat's blood. 



Since the reproductive stages of Tr. zicmanni show many resemblances to 

 iheSpiroductir, the latter, long regarded as Bacteria, may be llagellates. These 

 extremely dangerous organisms multiply bv longi- 

 ...'V tudinal division (the Bacteria by transverse), have 



a very motile corkscrew body, prolonged at either 

 end into a flagellum. Sp. pallida (lig. 142) cause 

 of syphilis; Sp. rcnirrcits, introduced by blood 

 sucking arthropods (ticks, lice), causes recurrent 

 typhus. Possibly I.;V.v/;»;((;//(!, which causes spleno- 

 megaly and the Alcpjio e^"il in man in warm 

 climates, belongs near here. 



Order II. Dinoflagellata (Cilioflagellata'l. 



These forms, occurring in both fresh water and 

 the sea, are placed near the plants because, with 

 their brown chromatophorcs, their food relations 

 are like those of plants, although the taking of 

 solid food by a mouth opening has been observed. 

 The armor formed of cellulose plates is also plant- 

 like. This armor is divided by a groove into two 

 parts which recall somewhat a box and its lid. 

 There is also a longitudinal furrow which crosses 

 the other. At the crossing arc two flagella; the 

 one in the trans\-erse groove was regarded as a 

 circle of cilia, whence the old name cilioflagellates 

 gi\'en the order. Pcrldiiiiiiiii laluilalum and Ccra- 

 tiiiin I'oruutum, fresh water (tig. 143); Ccratium 

 tripos,''<' marine. 



Order III. Cystoflagellata. 



The cystoflagellales, characterized by a gelatinous body surrounded by a 

 membrane, include three or four species', all marine, which' differ markedly in 

 external appearance. A^orlilnca miliaris* (tig. 144), is remarkably phos- 

 phorescent. These spherical forms, about i mm. large, sometimes occur in 

 such numbers at night as to make the sea light at the slightest agitation. 

 The phosphorescence is apparently caused by oxidation processes in the proto- 

 plasm. The body, a gelatinous sphere, is covered by a membrane, interrupted 



Fig. 143. — Ccratium coruii- 

 tum (after Stein). (Z/>(), ante- 

 rior horn with opening; aalt, 

 rsh, posterior and right horn ; 

 g, flagellum; ,!;,';, flagellar 

 groove; //', lonr;ilu(liiial 

 groo\'e; r, rhomboidal plate; 

 V, vacuole. 



