266 



The Journal of Heredity 



moist than would be the case where a 

 number of seminal roots developed. 



Thus under ordinary eonditions where 

 moisture is distributed through the 

 entire seed bed the seminal roots be- 

 come of little im]3ortance as soon as the 

 seedling is established and nodal roots 

 have developed. If a half grown or 

 nearly mature com plant is earefulh^ 

 dug up, the seminal roots and traces of 

 the seed can still be found but they are 

 usually dr\' and shrunken and are 

 obviously of little use to the plant. 

 This was also the condition found in 

 Navajo and Zuni maize fields, though 

 the seminal roots were more strongly 

 developed than in the eastern varieties. 

 But, in the more extreme conditions 

 existing in the fields near the Hopi 

 villages, where, as stated, the seeds were 

 planted deeper, it was found that the 

 seminal roots were relatively much 

 larger and w^ere still alive and fresh, 

 making it apparent that they retain 

 their function of supplying moisture, 

 and are able to play an important part 

 during the entire life of the plant. 



HOW THE MAIZE IS GROWN. 



In one field at the base of the first 

 Hopi Mesa the hills of maize were 

 planted about 20 feet apart with from 

 10 to 20 plants in a hill (sec Figure 11). 

 The soil was apparently pure sand 

 washed down by the winter rains and 

 entirely destitute of vegetation other 

 than the planted maize. An average 

 hill dug up in the field was found to 

 contain 15 plants ranging from 60 to 

 90 cm. in height. The remains of the 

 seeds were found at 25 cm. from the 

 surface and from each seed there de- 

 scended a single large seminal root. 

 These seminal roots were traced to a 

 depth of 35 cm. and extended even 

 farther down. They were still fresh and 

 densely covered with fine branches. 

 This mass of 15 seminal roots, while 

 less in volume than the nodal roots 

 arising near the surface, was apparently 

 playing an important ]3art in the su])- 

 port of the plants. The mesoeotyls 

 connecting the seminal roots with the 

 plants above, while dry on the outside, 

 were filled with live tissue quite unlike 

 the dry and shrunken mesoeotyls found 

 in plants of similar age grown under 

 more favorable conditions. 



When planted l)y the Indian methods, 

 the Hopi and Navajo varieties of maize 

 have been found superior to the more 

 improved eastern varieties for these very 

 dry regions. At the time of our visit 

 there was a small field near Keams 

 Canyon that had been planted b}' east- 

 ern methods. The plants were in rows 

 and thinned to one stalk to the hill. 

 There had evidently been a fair germina- 

 tion but the plants had died withotit 

 reaching maturity and had produced 

 no seed. At the same time in the 

 nearest Indian fields at Polacca the 

 plants were dark green and maturing a 

 fair crop, though the season was said 

 to have been unusually dry. 



Under extreme drought or other 

 unfavorable conditions the persistent 

 tendency of this type of maize to pro- 

 duce seed is very striking. Where any 

 growth is possible it seems to be 

 expended in the production of seed. 

 Many plants were seen where the 

 length of the ear was equal to one-half 

 the height of the entire plant. A plant 

 of this kind is shown in Figure 12. 

 With most of the improved varieties of 

 maize the ear is the first instead of the 

 last part of the plant to suffer when 

 unfavorable conditions are encountered. 



Even under irrigation the somewhat 

 larger strains grown by the Navajos 

 have been found to compare very favor- 

 ably with eastern types. Several acres 

 of Navajo maize were seen at Shiprock, 

 N. M., under irrigation. The fields 

 were very uneven, apparently the 

 result of alkali, l)ut in the better por- 

 tions the yield was good. The plants 

 were standing about two feet apart in 

 the row, the rows four feet apart, and 

 nearly every plant was bearing from 

 two to four fair sized ears (see Figure 

 13). The ears from 36 plants repre- 

 senting a number of distinct types were 

 collected. The 36 plants bore in all 

 94 cars weighing 37.6 lbs., an average of 

 15.2 oz. per plant. The plants produc- 

 ing these ears averaged only a little 

 over five feet in length. 



CONCLUSIONS. 



American agriculture is under ()l)Hga- 

 tion to the American Indian for liaving 

 devcloi)ed the maize plant to a high state 

 of efficiency and for having adapted 

 it to a wide range of environment. 



