Nutrition and Reproduction. 143 



XVI. 



NUTRITION AND REPRODUCTION. 



WHxA.T is the imme- 

 diate cause of re- 

 production? Wliat in- 

 forms the creature that 

 the time for providing for 

 future generations has 

 arrived ? 



To answer this question 

 let us return to the amcEba. 



We are told that a divi- 

 sion into two is necessary 

 in order that the creature 

 by diminishing its size may 

 obtain an adequate food 

 supply. Of course the bulk 

 of protoplasm which com- 

 posed the body would in- 

 crease much more rapidly 

 than the surface ; and as 

 food is received from the 

 surface only, there could 

 not be sufficient to nourish 

 the creature beyond a cer- 

 tain size. So the first cause 



