THE INFUSORIA 



381 



REPRODUCTION. In the simplest forms of INFUSORIA the mode 

 of reproduction in the motile phases of life is simple transverse 

 fission, but in the higher forms other methods of division occur 

 which are usually called longitudinal fission, simple gemmation, 



Az 2 



Fio. 29. 



Diagrams to illustrate the principal modes of division in the HETEROKARYOTA. 1, equal 

 transverse fission as in Paramoecium ; 2, unequal fission as in Stentor ; 8, longitudinal 

 fission as in Vorticella; 4, endogenous, unequal, and heteromprphic fission as in Tokophrya. 

 M, meganucleus ; m, micronucleus ; o, mouth ; c.v. t contractile vacuole ; G, geinmula ; Az, 

 adoral zone. (After Lang.) 



multiple gemmation, and spore-formation respectively. All of these, 

 however, are probably modifications of the same essential process, 

 which consists in the division of the three elements of the body 

 cytoplasm, meganucleus, and micronucleus into two or more than 

 two parts. 



In Paramoecium and Stylonychia, which may be taken as examples 



