CHAPTER FOUR. 

 REPRODUCTION BY BUDS 



1. Reviiew. In the lowly plants and animals which 

 were studied in the last chapter the offspring are 

 formed in the simplest possible way, that is, by merely 

 breaking up the parent into two or more equal parts of 

 the original organism. In this process the children do 

 not have to ask, "What shall we do with our parents?" 

 There are no parents left. Many writers have called 

 attention to the fact that in plants and animals of this 

 sort there is no death of the kind we described in an 

 earlier chapter. The parent sacrifices its individual 

 existence, to be sure; but the substance of which it is 

 made seems almost or quite able to renew its youth as it 

 divides, and thus to preserve itself from old age. Of 

 course these organisms may be killed by accident and 

 by unfavorable conditions. Untold millions of them are 

 destroyed by drouth, by cold, and by attacks of other 

 organisms, but probably not from mere old age. 



This method of reproduction is called division or fission. 



2. Budding of the Yeast. There is another group 

 of single celled plants, called yeasts, that are important in 

 human industries. They are used in the making of bread, 

 and in brewing beer, and fermenting wines; all this 

 because they have a wonderful power of producing 

 substances that change starches to sugar and break up 

 sugar into alcohol and gases. 



These plants are a little larger than the bacteria, but 



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