PARENTS AND OFFSPRING 45 



bud off from the old and the parent continues its own 

 life alongside the new ofTspring. Two offspring cost 

 much less of the body of the yeast parent than of bacteria. 

 In the case of spores, the sacrifice is still less. Only a 

 small part of the parent enters into them. 



4. The Size and Number of Offspring. In the bacteria 

 the two offspring are each just one-half the size of the 

 parent. The same is true of all other forms that 

 reproduce by simple division, as some worms. This is an 

 expensive method. Only two offspring are formed "in 

 these cases and the parent is entirely destroyed. In the 

 case of the yeast, the parent produces much smaller 

 offspring to start with and then allows it to grow up to 

 standard size. This is even more true in the forms th:it 

 produce spores. Many of these may produce thousands 

 of spores which are only a minute fraction of the size of 

 the parent plant. The parent may be completely used up 

 in this process or may use a part of its energies, leaving 

 some of its strength for reproduction some other time. 



5 How the Problem is Solved. It may help you to under- 

 stand what happens in different organisms if you see what 

 possible solutions there are. In reproducing, parents 



1. May be completely destroyed: 



(a) By producing two offspring, each one-half the 

 size of the parent, as in the bacteria and other 

 forms that simply divide. 



(b) By producing several or many minute offspring, 

 as in some cases of reproduction by spores. 



2. May not use up all their substance in reproduction: 

 (a) Producing a few young, but much smaller 



than one-half the parent when first produced. 

 Such are the budded cells in yeast or the 

 young strawberry plants formed by runners. 

 Here the offspring is of new substance made 

 by the parent rather than the old substance 

 of the plant itself. 



