66 



BOYS AND GIRLS IN BIOLOGY. 



This little jelly-splash appears to use its feet as we use 

 ours to walk with, though you w x ill see that it gets on 

 quite slowly and awkwardly. Its foot is called a pseu- 



Fig. 59. Fig. 61. 



The Amceba, or Blood-Cell, changing its Fobm. 



dopodium (Fig. 61), which means false-foot. These 

 little bodies have a very suitable name — amoebae, and 

 the word means changing. This name was given to 

 them because, as you have seen, they are constantly 

 changing their form. The amceba, or blood-cell, is 

 larger than the torula, or yeast-cell, and not quite so 

 large as the largest cell of the protococcus, or green 

 mould. It is usually about ytww °^ an i nc h ^ n breadth. 

 It does not possess a tough, woody, or cellulose sac, 

 like the yeast-cells or the PROTOCoccus-houses ; it is more 

 like the moving PROTOcoccus-boatmen. Its wall is just 

 the hardened outer layer of its own jelly, or pro- 

 toplasm. It has no vacuole, or thin space; no eye- 

 spot ; no cilia, or eyelashes ; and, when it is quite 

 fresh and new, you cannot see any nucleus, or kernel ; 

 you really can see nothing but an odd-looking lump 

 with here and there some little grains inside of it. If 



