o 



9 



O 9 

 C „ 



Spore* 



plant bit^s 



CHAPTER XXVI 



ASEXUAL 

 REPRODUCTION 



A moss capsule. 



Obelia forming buds. 



What is asexual reproduction? What kinds of organisms reproduce 

 asexually? What are some of the asexual methods of reyroductionf 



Only living things have the power to produce new organisms 

 similar to themselves. Schleiden, Schwann, and other scientists 

 showed that cells, living units of life, came only from preexisting 

 cells. This process of a cell or cells producing other cells is called 

 reproduction. It is a process peculiar to living organisms. Icicles, 

 crystals, stalactites, and stalagmites may grow by tiny additions to 

 the outside. These additions are known as accretions. After 

 accretion has gone on for some time, parts may break off. This 

 t\TDe of growth and division is fundamentally different from the 

 growth and division that come from within a living cell. A given 

 organism cannot live forever ; therefore, nature has provided, by 

 reproduction, a means of continuing the species. 



The necessity for division. In living cells, particles of food 

 material are taken into the cell bodv and made into cell material, 

 protoplasm, by the process of assimilation. This additional proto- 

 plasm causes the cell to grow. The cell grows until it becomes so 

 large that there is not enough surface to take in sufficient food for 

 the increased mass of protoplasm. By the process of dividing in 

 half, two more surfaces may be obtained, through which food may 

 be absorbed from the outside. After dividing, each cell again 



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