POPULAR GEOGRAPHY OF PLANTS. 



florets are tubular, and the involucre hard and almost 

 thorny, like the blue Corn-flower (Centaur ea Cyanus). 



We must by no means leave this northern Warmer Tem- 

 perate Zone without paying a visit to those wonders of the 

 Vegetable Kingdom which are to be seen in California : a 

 'journey of some three thousand miles across North America 

 will be easily performed in fancy, and we shall be amply 

 repaid. If, as was just now said, ninety feet is higher than 

 the highest trees we see in England, how great is our asto- 

 nishment as we reach the west of California, and mount the 

 lofty slopes of the Sierra Nevada, to find Eir-trees at an ele- 

 vation of 5000 feet, of the gigantic height of 250 and even 

 320 feet ! Within the circuit of a mile eighty or ninety of 

 these giants were not long since discovered, some ten and 

 some even twenty feet in diameter. The diameter of one 

 which was felled was more than twenty-nine feet ; and as 

 the rings of the wood in firs afford great facility in reckon- 

 ing the age of a tree, and the rate at which they grow is 

 believed to be two inches in twenty years, there is reason 

 to suppose that this tree must be above three thousand 

 years old : " that is to say, it must have been a little plant 

 when Sampson was slaying the Philistines, and Paris was 

 running away with Helen, and yEneas was carrying off good 



