376 ELEMENTS OF GENERAL SCIENCE 



Calculations which can be made in your class work will 

 show equally well what enormous numbers of individuals 

 would soon be produced if possibilities were allowed to be- 

 come realities. Jordan says, "An annual plant producing two 

 seeds only would have 1,048,576 descendants in twenty-one 

 years, if each seed sprouted and matured." It is a matter of 

 common knowledge, however, that the enormous reproduction 

 suggested by these figures does not really occur. 



388. Overproduction among animals. Animal reproduction 

 in enormous numbers is also inherently possible. A single 

 female codfish has been known to produce as many as 9,100,000 

 eggs in one year. A female salmon four years old may lay 

 4000 eggs. If half of these 4000 eggs grew into female 

 salmon and produced 4000 eggs each, as did their mother, 

 there would be 8,000,000 eggs. If we suppose that each of 

 these 8,000,000 eggs grows into an adult salmon four years 

 old and weighing 20 pounds (although four-year-old salmon 

 often weigh more than 20 pounds), there would be 160,000,000 

 pounds of salmon hi this third-generation crop. If these 

 salmon were packed hi tins and should net three fourths of 

 their original weight, or 120,000,000 pounds, and should be 

 sold at ten cents per pound, they would be worth $12,000,000 ; 

 or if the inhabitants of a city of 10,000 people were to use 

 an average of one fourth of a pound per day for each person, 

 the third generation of salmon would supply this city for 

 forty-eight thousand days, or for more than one hundred 

 and twenty-one years. 



Any given species of animal has an inherent rate of repro- 

 duction which makes enormous numbers of that species possible 

 if we assume that this inherent rate is to have no limitations. 

 Many an enthusiastic resident of a city has made calculations 

 regarding the number of chickens that may grow in a small 

 number of years from a small initial number of chickens. 

 Some city residents have even moved into the country ex- 

 pecting to grow chickens in numbers comparable to these 



