TJie Division of Labor. 27 



In the multiplication of the amoeba, as has been 

 noted, there is no death, merely the going on of 

 the whole mass in different directions. 



So in the spirogyra found in the scum of the 

 ponds, all the protoplasm of one cell passes into 

 and unites with all the protoplasm of the neighbor- 

 ing cell ; but the result is not quite the same, there 

 is some waste, some death here ; for when this 

 union has taken place, the cell-walls, no longer 

 useful, no longer kept intact by the contact of the 

 flowing protoplasm, disintegrate. 



They are empty houses, their tenants forever 

 departed. True, all that was living in them is still 

 living; the cell-wall in itself was no more alive 

 than is the end of one's finger-nail ; the protoplasm 

 built and nourished it, and when ready, left it. 

 And yet, when the spore formed there was an end 

 to the green filament, that form of its existence at 

 least perished. Only in its seed did it live, and 

 through that develop into green filaments another 

 year — not the same filaments, however. 



Simplest of all, the amoeba reproduced by divi- 

 sion, without the loss of any part of its substance, 

 and without undergoing any change of form. Then 

 we see the spirogyra preserving its whole mass of 

 living protoplasm, but giving up its green-banded 

 walls. 



This extreme simplicity in multiplying does not 

 belong to all of even the one-celled organisms, how- 

 ever, for some devote but a small portion of their 

 s 



