THE HUMAN AND THE POND AMOEBAE. 



67 



you give it a drop of weak vinegar, or acetic acid, its 

 granules will disappear, and you can see the nucleus, 

 or kernel, in the centre (Figs. 62, 63) ; you may find 



Fig. 62. Fig. 63. 



Kernel...— 

 Sac..— < 



Cells cleared with Vinegar, so as to show the Nucleus. 



it easily if you color the cell with magenta or weak 

 iodine. This nucleus seems to have something to 

 do with forming of new cells, as we shall soon 

 see. 



Heat makes the amceb^e move much quicker ; it is 

 very interesting to watch them make their way among 

 the colored cells, which lie all around them. Some- 

 times one of these crawling cells will clear a channel 

 for itself right through a thick group of the yellowish- 

 red cells (Fig. 64). The first time I ever saw one mov- 

 ing in this way, I could not help thinking of the canals 

 in Venice, where the gondoliers steer their gondolas 

 close beside the houses, turning the corners so skill- 

 fully, never striking them ; so this little gondolier of 

 the blood went in and out, threading its way among the 

 yellow cells which stood in rows like houses on either 



