AMCEBOID ORGANISMS. 55 
Naked cells, with kernels, like those represented in 
Fig. 10 B, which are continuously changing, stretching out 
and drawing in formless, finger-like processes, and which 
are on this account called amceboid, are found frequently 
and widely dispersed in fresh water and in the sea; nay,are 
even found creeping on land. They take their food in the 
same way as was previously described in the case of the 
Protameeba (vol. i. p. 186). Their propagation by division 
can sometimes be observed (Fig. 10 C, D.) I have described 
the processes in an earlier chapter (vol. i. p. 187). Many of 
these formless Amoebze have lately been recognized as the 
early stages of development of other Protista (especially 
the Myxomycetie), or as the freed cells of lower animals and 
plants. The colourless blood-cells of animals, for example, 
those of human blood, cannot be distinguished from Amcebe. 
They, like the latter, can receive solid corpuscles into their 
interior, as I was the first to show by feeding them with 
finely divided colouring matters (Gen. Morph. i. 271). How- 
ever, other Amcebze (like the one given in Fig. 10) seem to 
be independent “good species,” since they propagate them- 
selves unchanged throughout many generations. Besides 
the real, or naked, Amcebee (Gymnamcebe), we also find 
widely difiused in fresh water case-bearing Amcebee (Lep- 
amoebee), whose naked plasma body is partially protected 
by a more or less solid shell (Arcella), sometimes even by 
a case (Difflugia) composed of small stones. Lastly, we 
frequently find in the body of many lower animals parasitic 
Ameoebe (Gregarinz), which, adapting themselves to a para- 
sitic life, have surrounded their plasma-body with a delicate 
closed membrane. 
The simple naked Amcebee are, next to the Monera, the 
