ENVIRONMENT 89 



and the bulbs are smaller and nearer the surface 

 than those of the plants which grow where the 

 sun reaches them. 



On the other side of the same canyons the 

 bulbs grow larger and deep in the soil, and the 

 leaves and the blossoms transform themselves to 

 conserve moisture. 



Which was all that the cactus did when the sea 

 was turned into a desert. 



About the geysers of Sonoma County, and 

 scattered over other arid portions of California, 

 Arizona, and Mexico, there are a group of pines 

 (Pinus tuberculafaj muricata, attenuata, chihua- 

 huana) having most remarkable characteristics, 

 evidently having been subjected in long ages 

 past to frequent fires, probably often started by 

 the fires of this and other volcanic regions. The 

 ground in the vicinity of the locality chosen by 

 these pines is sometimes even yet so hot that it 

 is difficult to walk over it, even with heavy boots, 

 without burning the feet. There must have been 

 a time, as all the evidence shows, when fires were 

 quite common from volcanic action, and these 

 pines have learned a lesson which no other pines 

 or other coniferous trees on this earth have had 

 to learn. 



The cones of most pines take two years in which 

 to mature the seed, and all other pines open once 



