38 



GROWTH AND REPRODUCTION, 



CHAPTER V. 



GROWTH AND REPRODUCTION, 



THE process by which organisms give rise to fresh 

 generations is called Reprodicction. There are two 

 main types of reproduction, the asexual and the sexual. 



Fig- 13.— Diagram to Illustrate Changes of the 

 Nucleus (N) during Cell-Divisiot^j. 



N grows to 2N. 

 2N divides into two. 

 Each grows to 2N. 

 Each divides into two. 

 Each product grows to 2N. 



Each product divides into 

 two. 



&c. 



Asexual Reproduction. — In asexual reproduction a 

 single individual divides into two or more parts or portions. 

 When the individual splits into two parts, approximately 

 equal in bulk, the reproduction is called binary fission; 

 when into many equal parts it is called nmltiple fissioji. If 

 the division is into two or more parts of which one is much 

 the larger, the process is distinguished as budding \ the 

 lesser part is termed the biid^ the larger is known as the 



