A Forest of Stone. 101 



before the observer's eye from green to brown. The 

 locusts were a common pest here, and often threat- 

 ened the crops of the natives, their only salvation 

 being to wage a war of fire against them. 



Crossing the Luxan, the village of that name was 

 reached, where the night was spent in repelling the 

 attacks of the reduvius a black bug that is a most 

 courageous blood-sucker. To test the pugnacity of 

 this creature Darwin placed one upon a table, where, 

 if a finger was pointed at it, the blood-thirsty insect 

 would protrude its sucker and charge at it. 



Of the people of Mendoza Darwin quotes the 

 description of Sir F. Head : " They eat their dinners, 

 and it is so very hot they go to sleep and could 

 they do better?" Darwin adds: "I quite agree 

 with Sir F. Head : the happy doom of the Mendo- 

 zinos is to eat, sleep, and be idle." 



Darwin returned to Chili by the Pass of Uspallata, 

 and here also he made careful geological studies. 

 To show his prescience, upon discovering a layer of 

 tertiary beds resembling some in which he had 

 found fossil trees, he began to search for them here 

 with most satisfactory results, as in the central por- 

 tion of the range, a mile above the sea, he noticed 

 numbers of snow-white columns projecting from a 

 cliff. Here was a forest of stone, one of the most 

 interesting finds he made, the trees extending in 

 every direction, some silicified, and others coarsely 

 crystallised white calcareous spar. Nearly all were 

 broken off near the ground, and were from four to 

 five feet in circumference. Darwin took sections of 

 them as specimens, and found that they were firs, or 



