72 



BOYS AND GIELS IN BIOLOGY. 



around it and at once begins to digest it, and all parts 

 that cannot be used are poked out again. The cells 

 that are swallowed are like so many jars of " Liebig's 

 Extract ; " all that the amoeba has to do is to suck out 

 the meat, or protein, and throw out the empty jar, or 

 cell-wall. There is something you must remember 

 about the amoeba — it must have its food, or protein, 

 ready made. It has no power, like the torula or pro- 

 tococcus, to manufacture its own food from the raw 

 material. So this little creature that goes crawling 

 through our blood must be an animal ! You recollect 

 all vegetables make protein, while all animals eat it 

 up. This little animal gets its full share — it is a per- 

 fect little gourmand, taking in every thing that comes 



Fig. TO. Fig. 71. Fig. 72. 



"Wild Amceba. Human Amcbba. Amosba making a Foot. 



in its way. The human amceba seem to be more fas- 

 tidious in their tastes and manners, they do not swal- 

 low their food whole like the wild amcebjs ; but those 

 of the frog and newt are regular little cannibals, and 

 eat up their " colored brethren " whenever they get the 



