ART. 3 A FOSSIL PALM FRUIT FROM PERU BERRY 6 



more or less periodic increase in strength from unknown causes, as 

 in February, 1925 when it brought floods to the semidesert coastal 

 region of northwestern Peru, could doubtless carry such palm fruits 

 as the present fossils southward, at least as far as Negritos, Peru, 

 the locality where the fossils Avere collected. My son, E. Willard 

 Berry, reports Entada and other drift fruits from the wet tropics 

 to the north, as having reached Negritos tliis February (1920) 

 during a somewhat less severe repetition of the climatic upset of 

 1925. 



Another alternative that may be mentioned is that the palms which 

 furnished these fossil fruits grew inland and east of an Eocene 

 mountain axis which was high enough to bring about conditions 

 like those of the present time in this region, and that these fruits 

 were transported to their final resting place by rivers w^hich crossed 

 this divide, which is negatived by the abundance of these fossil 

 fruits. Granting the altogether unlikely presence of such a river, it 

 would hardly be expected to deposit numerous individuals of a single 

 species at one spot, unless perhaps their floating powers and the 

 action of the waves or some combination of eddies or currents in 

 the estuary or at the place of debouchure of such a river might be 

 regarded as a selective agency. It seems to me that such a combina- 

 tion of events is so remote as to rule out this supposition altogether. 



The third alternative is that these fossil fruits were from trees 

 growing in the vicinity where they were fossilized. Personally I 

 can not see the evidence for a great mountain axis in Eocene times 

 making a semidesert of coastal Peru, and I believe, that, irrespec- 

 tive of the exact character of the Atlantic-Pacific divide in the 

 earlier Tertiary, it was not sufficiently elevated to prevent the Pacific 

 coast from receiving a greater rainfall than it receives at the present 

 time, as is proven to have been the case during the lower IVIiocene.^ 



If the present species of Astrocaryu?)i could be proven to have 

 grown in the neighborhood of where its fruits were found fossil it 

 would prove the humidity of the middle Eocene climate of coastal 

 Peru. As it is the only described terrestrial plant known from this 

 horizon in this region, it can not be considered to have any decisive 

 weight. I am inclined to interpret its ecological message as indi- 

 cating such a humid environment. This inclination is not due to 

 my belief in the late Tertiary elevation of the Andes, but rests on 

 the presence of a considerable flora in the Oligocene of that region. 

 This Oligocene flora is made up of the silicified fruits and seeds of 

 nearly a score of species, many of which could not withstand water 

 transportation and hence must have grown near where they occur as 

 fossils. These Oligocene plants indicate a climate with a rainfall 



'Berry, Edward W., Proc. U. S. Nat. Mua, vol. 55, pp. 279-294, 1919. 



