348 



FIG. 92. Apricot blossoms 

 growth from stored food. 



Plant Physiology 



production of seed is for most 

 plants of paramount importance. 

 Vegetative methods of repro- 

 duction may also occur in plants 

 possessed of the power of abun- 

 dant seed production ; and, in- 

 deed, under favorable circum- 

 stances the former may propagate 

 individuals more rapidly. Sup- 

 plementary vegetative methods 

 of reproduction are therefore 

 common. Wild onions and lilies 

 may have their " sets ' and 

 bulbs. Numerous plants develop 

 offshoots, root shoots, and natural 

 layers, and so perpetuate them- 

 selves in a variety of ways. A 

 few plants both wild and cul- 

 tivated, such as forms of the water 

 weed and the yam, have entirely 

 or practically lost the power of 

 seed-making. In general, how- 

 ever, the seed is the basis of plant 

 production, although vegetative 

 reproduction has been employed 

 far beyond its natural course, and 

 this in order to perpetuate a type, 

 to multiply individuals quickly, 

 and to grow plants under climatic 

 conditions rendering seeding un- 

 profitable or impossible. 



