CHAPTER XXXII 

 THE STRUGGLE FOR EXISTENCE 



385. Questions for Discussion. 1. It is not uncommon for high- 

 grade hens to lay as many or more than 200 eggs each in a year. If 

 all these eggs should be hatched and all the chickens live, and if half 

 of the chickens should become laying hens the succeeding year for 

 five years, how many chickens might there be as descendants of one 

 hen at the end of the five-year period? 2. A good many city people 

 have become enthusiastic about moving to the country and raising 

 poultry because they have calculated how many fowls might possibly be 

 produced from a small number. What are some of the factors often 

 omitted iu these calculations? 3. The rate of reproduction inherently 

 possible if unlimited would permit one stand of honeybees to produce 

 enough bees so that in six years Illinois would not furnish standing 

 room for all the hives. Why cannot these enormous figures be realized 

 in fact? 4. How do calculations regarding overproduction help to make 

 it clear that there is a struggle for existence ? 5. A mourning dove has 

 frequently been known to devour more than 5000 weed seeds in a single 

 day. Suppose, as is unlikely, that one pair of mourning doves should 

 devour seeds at this rate for the three summer months, how many 

 would they devour in that time ? Do you think they really do devour 

 seeds at this rate all summer? 6. In what way may such birds help 

 the farmer in his own struggle for existence ? 



386. The fight for life. If we observe a dense forest or a 

 wheat field we see that there are many kinds of plants that 

 are living under the shade of taller plants. Some of the shaded 

 plants seem to be thriving, and others may show by their con- 

 dition that they are not doing well. Along a country roadside 

 also or in a vacant lot a great number of plants often start 

 to grow in a relatively small space. By observing such a 

 region at successive periods for some weeks it will usually 

 be seen that fewer and fewer plants persist ; and by the time 



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