50 CHARLES DARWIN 



developed in distinct species of their later descend- 

 ants. 



Still more pregnant with evolutionism in the bud is 

 the prophetic remark about a certain singular group of 

 South American birds, ' This small family is one of those 

 which, from its varied relations to other families, 

 although at present offering only difficulties to the 

 systematic naturalist, ultimately may assist in revealing 

 the grand scheme, common to the present and past ages, 

 on which organised beings have been created.' Of the 

 agouti, once more, that true friend of the desert, 

 Darwin notes that it does not now range as far south as 

 Port St. Julian, though Wood in 1670 found it abundant 

 there ; and he asks suggestively, ' What cause can have 

 altered, in a wide, uninhabited, and rarely visited 

 country, the range of an animal like this ? ' Again, 

 when speaking of the analogies between the extinct 

 camel-like macrauchenia and the modern guanaco, as 

 well as of those between the fossil and living species of 

 South American rodents, he says, with even more pro- 

 phetic insight, * This wonderful relationship in the same 

 continent between the dead and the living will, I do 

 not doubt, hereafter throw more light on the appearance 

 of organic beings on our earth, and their disappearance 

 from it, than any other class of facts.' He was him- 

 self destined in another thirty years to prove the truth 

 of his own vaticination. 



A yet more remarkable passage in the c Journal of 

 the " Beagle," ' though entered under the account of 

 events observed in the year 1834, must almost certainly 

 have been written somewhat later, and subsequently to 

 Darwin's first reading of Malthus's momentous work, 



