60 



PLANTS AND MAN 



tary consideration of plant life, as well as necessary to control the 

 amounts and types of seeds and fruits produced. One will 

 appreciate flowers all the more for a knowledge of how they func- 

 tion. Flower and seed production would be difficult to compre- 

 hend without the preceding survey of the stages which constitute 



SPORANG/A- 

 BEARING 

 LEAF 



. •/ SPORES 



ASEXUAL PLANT 



GAMETES 



GERM /NAT/ ON 



SEXUAL PLANT 



Fig. 34. — The life history of a fern plant. 



the basis of evolution of reproductive habits in the simpler plants; 

 an evolutionary sequence which begins with fission in the uni- 

 cellular algae and culminates in flowers, seed formation and 

 ingenious methods of fruit dispersal. 



A SEED is an embryo sporophyte, protected within various 

 coats and surrounded by stored food upon which it can feed 



