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THE POPULAR SCIENCE MONTHLY 



is put out as far as it can reach, then the body all runs into the foot, 

 and another foot is stuck out from some other part, and away goes the 

 body into this new foot. So it gets on, the feet actually swallowing 



Fig. 29. Grains flowing 

 into Foot. 



Fig. 30. Trying to walk. 



Fig. 31. Stained 

 with Magenta. 



the body ! The toad sometimes swallows its old skin, but the amoeba 

 is the only animal I know which is " taken in " by its feet ! How odd 

 it would be, if, as you walk along, you should suddenly disappear into 

 your boots ! If you crush the amoeba, you find no trace of a tough 

 sac such as you found in the yeast and protococcus cells. You can see 

 nothing but the kernel or nucleus, and even that soon disappears. If 

 you stain with magenta or iodine, the whole cell becoms colored alike. 

 If there were a tough, woody sac, as in the yeast and mould, it would 

 not be stained. The iodine does not give it a blue color, so there 

 cannot be any starch in the amcebre. The amoeba? grow like the green- 

 mould cells, by fission, that is, by one or two partitions made through 

 the old cells. You will first see two kernels appear in one of the old 

 cells ; then, by close watching, you see a partition going right down 

 between the kernels, separating the old cell into two, with a kernel or 



-- Partition between the 

 two kernels. 



w 



nucleus in each. Each new cell follows in the footsteps of its ances- 

 tors, crawling, eating, and growing, in the same way. And now I 

 hope you have learned enough about this curious amcebce family to 

 put your wits to work and give us, some day, a full history of them, 

 and tell us of what use they are, and what they mean by all their 

 motions. 



Boys, and girls too, sometimes, love to wade in ditches and ponds 

 in warm weather. When you are thus wading, some time, if you will 

 take up a piece of the duck-weed that grows on the surface of the 

 water, you may see a number of slender green, brown, or orange-col- 



