46 REPRODUCTION 



(b) Producing a large number of minute young in 



particular portions of the body. Not all the 



parent is used up. This is the case in many 



plants. 



It should be remembered that many organisms which 



are not actually destroyed outright by the formation of 



their young are still so exhausted by producing and 



maturing them that they die, and do not reproduce again. 



All our annual herbs would fall in this class. The same 



is true of some animals, as the salmon, which is often so 



exhausted by reproducing that death follows. 



6. The Problems Related to the Size and Number of 

 the Offspring. We know that in the long run an animal 

 or plant needs to bring only one of its offspring to 

 complete maturity during its own life in order to leave 

 the species as well represented as before. But there are 

 many disasters between the young and their maturity. 

 Therefore very many more must be produced than will 

 ever come to maturity. This is true of all organisms. If 

 all the offspring that any species can produce were to 

 live and mature and produce indefinitely, that species, 

 in a few years, would become a pest. Many must be 

 produced in order to insure one. 



Now the advantage in having offspring like the bacteria, 

 one-half grown at birth, is very clear. It only takes a 

 little time for it to become adult, and the dangers that it 

 will not do so are less than if it were one-thousandth part 

 of the adult. On the other hand, the parent is completely 

 destroyed and we have only two of the half-grown 

 offspring instead of the one adult. The advantage of a 

 form that produces thousands of small offspring is that 

 there is more chance of one in a thousand surviving than 

 of one in two, and beside they can be scattered over a 

 wider territory and this increases their chances. On the 

 other hand, these small young have much further 

 to go in developing and the chances of disaster 



