THE VEGETABLE KINGDOM. 491 



the most sterile rocks, where the eye with difficulty detects 

 a few particles of earth. How can a plant so bulky, fleshy, 

 and watery grow without taking up anything from the 

 soil, and draw the elements of nutrition from the burning 

 air around it ? When this cactus is fully developed, it pre- 

 sents the appearance of an immense chandelier, attaining a 

 height of as much as sixty feet, and it is surprising to see 

 that the tempest spares it. 



When we pass from animals to the vegetable kingdom, 

 we find that, notwithstanding the calm and silence which 

 here preside over all the acts of life, there is yet an energy, 

 a tenacity, which one would never have suspected. To the 

 extremes of size are opposed incalculable differences in 

 duration. No animal grows with the prodigious rapidity 

 which we see in certain plants, nor does any attain the fab- 

 ulous longevity which is the attribute of many trees. 



One plant passes away like the last hour of the Ephemera 

 which flutters in the twilight over the banks of our streams ; 

 a ray of sunlight sees its birth and fall. Another defies the 

 power of ages ; the offspring of creation, it seems as if it 

 ought only to sink with the wreck of the globe. 



Some of our more common moulds pass in one day 

 through all the phases of life ; this lapse of time is sufficient 

 for them to appear in, fructify, and die. But by a singular 

 contradiction, some plants of the same class only grow with 

 inexplicable slowness. One of those lichens, which show 

 like plates of golden yellow on the roofs of our houses, was 

 watched for forty years by Vaucher, without his seeing that 

 it increased to a perceptible extent. Accordingly, De Can- 

 dolle said that the lichens which cover our rocks possibly 



