GENERAL ANIMAL FUNCTIONS. 87 



individual cells may continue to live, for a time, after the 

 death of the animal. 



94. Reproduction. In the light of the tendency of or- 

 ganisms to lose the powers of growth and division result- 

 ing in what we call old age and death organisms could 



FIG. 14. Direct cell division (ameeba). A, active specimen with pseudopodia ; 

 B, becoming spherical, preliminary to division; C-E, stages in division, ec, clear outer 

 protoplasm; en, granular inner protoplasm; /, food vacuole; n, nucleus; ps, pseudo- 

 podium ; v, pulsating vacuole. 



Questions on the Figure. Why is this appropriately called direct 

 division? What structures are divided? Are the resulting halves 

 exactly or merely roughly equal, apparently? Do you see any 

 possible gain to the organism in dividing? 



not have persisted and increased on the earth but for the 

 power to form new and young individuals, whose cells are 

 not old. This is called reproduction. Reproduction, then, 

 must include two things: (i) it must produce new individ- 

 uals', and (2), what is quite as important, the new indi- 

 vidual must be young again ; that is, it must not inherit 

 the age which the parent had at the time of reproduction. 

 All organisms have this power of producing new individ- 



