A FOSSIL EAR OF MAIZE 



First Tangible Evidence of the Existence of Indian Corn in Geologic Times 



G. N. Collins 

 Bureau of Plant Industry, United States Department of Agriculture, Washington, D. C. 



DR. F. H. KNOWLTON has re- 

 cently published the description 

 of a fossil ear of maize from 

 Peru.^ The specimen, which is 

 described as a new species, Zea antiqua 

 Knowlton, was purchased from a col- 

 lector of curios in Cuzco, Peru, in 1914. 

 In spite of its unsatisfactory history, 

 the specimen is of especial interest since 

 it affords the first tangible evidence of 

 the geological existence of this impor- 

 tant cultivated plant. 



It is well known that maize or Indian 

 corn was grown widely in North and 

 South America before the time of 

 Columbus. How long before, there is as 

 yet no way of determining. A very 

 long period is indicated by the fact that 

 the progress made in the improvement of 

 this plant since the discovery of Amer- 

 ica is insignificant in comparison with 

 the changes that must have taken place 

 since the prototypes of maize were able 

 to exist as wild plants. Not only v^-ere 

 the kinds found growing by the earliest 

 explorers similar to those now culti- 

 vated, but remains of ears found in 

 prehistoric graves are almost duplicates 

 of the varieties grown in the same 

 regions today. 



The finding of a fossil ear means that 

 the origin of maize may now be trans- 

 ferred from prehistoric to geologic times, 

 for Dr. Knowlton is confident that, 

 although the specimen may not be 

 assigned to its exact geological period, it 

 is an undoubted fossil. Yet the type it 

 represents is tlomesticated maize essen- 

 tially like the varieties still being grown 

 in Peru and Bolivia. 



Mexico is generally thought to be the 



region where maize was originally do- 

 mesticated. The chief reason for as- 

 signing the origin of maize to Mexico 

 rather than to South America is the 

 important fact that Mexico is the natur- 

 al habitat of teosinte, the nearest wild 

 relative of maize. On the other hand, 

 the great diversity of types existing in 

 South America certainly bespeaks either 

 a very great antiquity or a multiple 

 origin. 



Prior to the discovery of Zea antiqua 

 the most ancient evidence of maize was 

 the specimens found by Darwin^ who 

 tmearthed "heads of Indian corn," 

 mixed with marine shells and earth on 

 an elevated ledge on the island of San 

 Lorenzo near Callao, Peru. The ledge 

 on which the relics of maize were found 

 was elevated 85 feet above sea level. 

 The shells which accompanied the 

 maize specimens belonged to recent 

 species and were covered with a few 

 inches of detritus. Darwin states that 

 the maize and human remains "had 

 all indisputably been embedded with 

 the shells." 



The ear of Zea antiqua is 60 mm. long 

 and 35 mm. in greatest diameter. The 

 apical portion is missing but the original 

 ear must have been about 80 mm. in 

 length. The butt is rounded and the 

 ear is strongly tapered, there being no 

 portion even approximately cylindrical. 



The seeds are from 4 to 8 mm. in 

 length and from 3 to 5 mm. in width, 

 sharply pointed and irregularly dis- 

 posed. The seeds on one side of the ear 

 at some distance from the base are 

 somewhat smaller and more irregular in 

 form, making the ear slightly asymmet- 



1 Jour. Wash. Acad, of Sci., Vol. 9, No. 5, pp. 134-136, March 4, 1919. 



2 Darwin, C. R., "Geological Obserwations on Coral Reefs, Volcanic Islands and on South 

 America," Pt. II, pp. 47-49, London, 1851. 



170 



