Collins: Prehistoric JNIaize 



63 



THE ARICA EAR AS FOUND IN A 

 PREHISTORIC GRAVE 



Figure 2. The grave was excavated in 

 the face of a cliff on the coast of Chile, in 

 a region where no maize is grown today be- 

 cause of extreme scarcity of water. Re- 

 mains of irrigation works indicate that the 

 ancient inhabitants brought water for their 

 crops from the distant mountains. This re- 

 gion gives evidence of having been the home 

 of a numerous prehistoric people, but just 

 how long ago they lived is not known. 

 When the Spaniards arrived the coast of 

 Chile was as much a desert as it is today. 



is found only in unimproved varieties 

 grown by native tribes. Many of these, 

 however, have ears fully as tapering 

 as in the prehistoric form. C^n the 

 other hand, the rounded butt with 

 grains extending over the base of the 

 ear usually is considered a mark of 

 good breeding. The strikingly small 

 ear stalk of both the fossil and Arica 

 specimens is a character much de- 

 sired in commercial varieties on ac- 

 count of the ease in shucking, and no 

 existing variety is known with ear 

 stalks so slender as those of the fossil 

 and the Arica specimens. 



Number of Rozvs : The large num- 

 ber of rows of spikelets on the ear 

 and the central spike of the tassel is 

 one of the most striking characters 



that separate maize from all related 

 grasses. It would be expected, there- 

 fore, that a truly primitive form would 

 have a small number of rows. In 

 modern varieties the number ranges 

 from eight to something over thirty 

 but it is not certain that the eight-rowed 

 types are more primitive or less highly 

 specialized. Eight-rowed varieties are 

 most common near the northern limit 

 of the geographic range of maize and 

 where they reappear in South America 

 it is in connection with the highly spe- 

 cialized, large-seeded Cuzco and re- 

 lated varieties grown at relatively high 

 altitudes. 



The irregular arrangement of the 

 grains in both specimens makes it im- 

 possible to determine accurately the 

 number of rows. There are, however, 

 at least twenty in the Arica specimen 

 and probably twenty-two in the fossil 

 ear. These numbers are well above 

 the average of modern varieties. 



Arraiigcmcut of Grains : The lack 

 of regularity in the arrangement of 

 the grains may be considered a primi- 

 tive character if the ear is assumed 

 to have originated by the shortening 

 and twisting of a four-rowed spike. 

 But if the ear originated through the 

 fasciation of lateral four-rowed 

 branches the irregularity must repre- 

 sent a specialization of the original 

 form. Irregularly disposed grains are 

 a common variation in many varieties 

 but are characteristic of none except 

 the sweet variety, "Country Gentle- 

 man," where the irregularity is due to 

 the development of both of the flowers 

 of the spikelet. In the Arica speci- 

 men only one flower is developed in 

 the spikelet. 



Size of Grains : The grains are 

 small but not smaller than in many va- 

 rieties of pop corn. Since the endo- 

 sperm of the Arica specimen is com- 

 posed of soft starch the specimen may 

 not be called a pop corn and since 

 these specimens represent the smallest 

 grains with soft endosperm the small 

 size perhaps may be looked upon as 

 primitive. 



