48 Structure and Classification of Micro-organisms 



undulating membrane to the anterior extremity, where it continues 

 free for some distance. Nutrition parasitic. Reproduces by 

 division. 

 Genus Trypanosoma. 

 Genus Leishmania. 



Genus Babesia. . 



Family SpirochatidcB. Organisms very long and spirally twisted. 

 Nucleus indistinct. Multiplication probably by longitudinal 

 division only. Nutrition is parasitic or saprophytic. 

 Genus Spirochsta. Body flattened, with a very narrow undulating 



membrane. 

 Genus Treponema. Body not flattened. No undulating membrane. 

 Extremities sharp pointed and terminating in short flagella. 

 Class Sporozoa (o-iropos a spore, fioy an animal). Organisms unprovided 

 with cilia or flagella in the adult stage. Always endoparasites in the 

 cells, tissues, or cavities of other animals. Nutrition is parasitic and 

 osmotic. Reproduction always by spore-forrhation, the sporozoites 

 either being produced by the parent or indirectly from spores, into 

 which the parent divides. 

 Subclass Telosporidia. Spore-formation ends the individual life, the 

 entire organism being transformed to spores. 

 Order Gregarinida. Possess distinct membrane with myonemes 

 during adult life; locomotion mainly by contraction. Young stages 

 alone (cephalonts) are intracellular parasites, the adults (sporonts) 

 being found in the digestive tract or the body cavities. Sporulation 

 takes place after or without conjugation, but within a cyst that is 

 never formed, while the parasite is intracellular. 

 Order Coccidiida. Spherical or ovoid in form, without a free and 

 motile adult stage. Never ameboid. Sporulation takes place 

 within cysts formed while the organism is an intracellular parasite. 

 Genus Coccidium. 

 Genus Eimeria. 

 Order H^mosporidiida. Sporozoa of small size living in the blood- 

 corpuscles or plasma of vertebrates. The adult form is mobile 

 and in some cases provided with myonemes. Reproduction by 

 endogenous or asexual sporulation, while in the host or by ex- 

 ogenous sporulation after conjugation. 

 Genus Plasmodium. 

 Subclass Neosporidia. Organisms that form sporocysts throughout life, 

 the entire cell not being used up in the formation of the spores. 

 Order Sarcosporidia. The initial stage of the life history is passed 

 in the muscle cells of vertebrates. Form is elongate, tubular, 

 oval, or even spherical. Cysts have a double membrane, in which 

 reniform or falciform sporozoites are formed. 

 Genus Sarcocystis. 

 Genus Miescheria. 

 Genus Balbiania. 

 Subclass Haplosporidia. Spores provided with large round nuclei. No 

 polar capsules. 

 Genus Rhinosporidium. 

 Class Infusoria (Latin, infusus, to pour into. The organisms were given 

 this . name because they were first found in infusions exposed to the 

 air). Protozoa in which the motor apparatus is in the form of cilia, 

 either simple or united into membranes, membranelles, or cirri. The 

 ciUa may be permanent or limited to the embryonic stages. There 

 are two kinds of nuclei, macronucleus and micronucleus. Reproduc- 

 tion is effected by simple transverse division or by budding. Nutrition 

 is holozoic or parasitic. 

 Subclass Ciliata. Mouth and anus usually present. The contractile 

 vacuole often connected with a complicated system of canals. 

 Order Holotrichida. The ciha are similar and distributed all over 

 the body, with a tendency to lengthen at the mouth. Trichocysts 

 are always present, either over the whole body or in special regions. 

 Genus Colpoda. 

 Genus Chilodon. 



