182 FAMILY: AM(EBID^ 



mice fed ou the latex of the plants or injected intrapeiitoneally with cultures of the 

 amoebae and flagellates acquired liver abscess in which amcebse with included red 

 corpuscles occurred. These amoebae are said to reproduce by schizogony, and give 

 rise to forms like anaplasma, leishmania, and trypanosomes. The figures purporting 

 to show these forms are quite unrecognizable, and it is impossible to understand the 

 ai;thor"s conception of these Protozoa. 



Genus: Pelomyxa Greef, 1874. 



This genus includes certain large free-living multinucleate amoebae, 

 which may reach a diameter of 2 millimetres. They occur commonly in 

 stagnant water, and are easily visible to the naked eye. Each individual, 

 which may contain several hundred nuclei, moves slowly as it throws out 

 blunt pseudopodia (Fig. 92). The character of the cytoplasm varies with 

 the medium in which the organism is growing. It is usually much vacuo- 

 lated, and may be packed with small globules of a refringent substance. 



Fig. 92. — Pelomyxa lyalustris : Ordinary Condition during Active Movement 

 (x 1,000). (After Cash, 1905.) 



in addition to sand grains, diatoms, bacteria, and other objects, which 

 cause it to be peculiarly opaque. At other times the globules are absent, 

 and the cytoplasm is much clearer. Reproduction takes place by fission, 

 while gamete formation has also been described by Bott (1906). It is 

 supposed that uninucleated individuals are divided off, and that these 

 conjugate in pairs to give rise to zygotes, which grow into the multinucleated 

 adults (see p. 30). 



Genus : Entamoeba Casagrandi and Barbagallo, 1895. 



The members of this genus, which inhabit the intestine of higher 

 animals, vary in diameter from 5 to 40 microns. The pseudopodia are 

 usually blunt processes, and a new one is rarely formed before the previously 

 existing one is withdrawn. A central endoplasm can be distinguished 

 from a peripheral ectoplasm, while a contractile vacuole is not present. 



