THE REPOSE OF PLANTS. 213 



as fuel, or whether the evolution of heat and the formation of car- 

 bonic acid are incidental consequences of certain necessary trans- 

 formations. We have remarked that the principal consumption 

 takes place in the flower ; and that a store is laid up in the fruit 

 and seed. But much even of this is consumed, with the evolution 

 of heat, when the seed germinates. By a not very violent met- 

 aphor it may be said, therefore, that in the Century-plant (369), 

 which, after living a hundred years, consumes itself in producing 

 and giving life to its offspring, who literally rise from its ashes, we 

 have the realization of the fabled Phoenix ! 



374. Plants need a Season Of Rest, There is another condition, 

 which, if not essential to the production of flowers, exerts an im- 

 portant influence. When plants are in continual and luxuriant 

 growth, rapidly pushing forth leafy branches, they are not apt to 

 produce flower-buds. Our fruit-trees, in very moist seasons, or 

 when cultivated in too rich a soil, often grow luxuriantly, but do 

 not flower. The same thing is observed when our Northern fruit- 

 trees are transported into tropical climates. On the other hand, 

 whatever checks this continuous growth, without affecting the 

 health of the individual, causes blossoms to appear earlier and 

 more abundantly than they otherwise would. It is for this rea- 

 son that transplanted fruit-trees incline to flower the first season 

 after their removal, though they may not blossom again for several 

 years. A season of comparative rest is essential to the transfor- 

 mation by which flowers are formed. It is in autumn, or at least 

 after the vigorous vegetation of the season is over, that our trees 

 and shrubs, and most perennial herbs, produce the flower-buds of 

 the ensuing year. 



375. The requisite annual season of repose, which in temperate 

 climes is attained by the lowering of the temperature in autumn 

 and winter, is scarcely less marked in many tropical countries, 

 where winter is unknown. But the result is brought about, in the 

 latter case, not by cold, but by excessive heat and dryness. The 

 Cape of Good Hope, the Canary Islands, and the southern part 

 of California, may be taken as illustrations. In the Canaries, the 

 growing season is from November to March, the winter of the 

 northern hemisphere, their winter also, as it is the coolest sea- 

 son, the mean temperature being 66 Fahr. But the rains fall reg- 

 ularly and vegetation is active ; while in summer, from April to 

 October, it very seldom rains, and the mean temperature is as high 



