64 Charles Darwin. 



Behring's Straits and on the plains of Siberia, we are 

 led to look to the north-western side of North Amer- 

 ica as the former point of communication between 

 the Old and so-called New World. And as so many 

 species, both living and extinct, of these same genera 

 inhabit and have inhabited the Old World, it seems 

 most probable that the North American elephants, 

 mastodons, horse, and hollow-horned ruminants mi- 

 grated, on land since submerged near Behring's 

 Straits, from Siberia into North America, and 

 thence, on land since submerged in the West Indies, 

 into South America, where for a time they mingled 

 with the forms characteristic of that southern conti- 

 nent, and have since become extinct." 



While travelling through this region, Darwin 

 learned that between the years 1827-30, a terrible 

 drought had occurred, during which myriads of 

 animals had perished. He was told that wild 

 deer became so thirsty that, devoid of fear, they 

 came into the yards of native houses and endeav- 

 oured to obtain water from the wells; while game 

 birds could be caught by the hand. It was esti- 

 mated that one million head of cattle were lost 

 during this time. 



A most interesting deduction from facts obtained 

 here was made by Darwin. He learned that many 

 animals frenzied with thirst rushed down the banks 

 of streams in herds, and were often so weak that 

 they were unable to climb up again. Then followed 

 the flood, and their bodies were washed away and 

 buried. He concluded that several hundred thou- 

 sand creatures may easily have been destroyed at 



