THE GROWING OF CORN. 88 



correct, as it seems to be, would show that in plants, as in 

 animals, crossing brings about strength. The crop of 1879 

 was from a cross of the Longfellow and the Waushakum 

 corn, — two seed-corns of similar appearance ; this crop of 

 1880, from selected ears of last year's crop, and selected in 

 the direction towards which the Waushakum corn has been 

 bred. The seed of this year will be bred with the Wau- 

 shakum corn in order to secure in this corn the good points 

 already outlined. Except for selection, this crossing of corn 

 would be of avail only for a single crop, and the seed thus 

 gained would become grade instead of thorough-bred. 



Having now treated of the seed, — the most difBcult point 

 to secure perfection, or even maximum yield, than any other, 

 — we will pass to the cultivation of the crop. 



PLOUGHING. 



Experiments have clearly shown that the corn-roots ex- 

 tend the most rapidly in soil that is rich, moist, and of the 

 proper temperature. How, in culture, can we secure these 

 conditions ? 



The temperature of the soil is acquired through the sur- 

 face, the heat being originally from the sun, and transmitted 

 downward. The study of soil-temperatures in this connec- 

 tion is rather a difficult one, as the heat of mid-day becomes 

 equalized in the night, and the maximum temperatures con- 

 cern us, Us well as the mean temperatures of the day and 

 night. In general, the maximum temperatures during the 

 growing seasoti of the crop are near the surface, while there is 

 a considerable uniformity of the mean temperatures at four 

 inches, six inches, and two feet of depth. Where this maxi- 

 mum temperature exists, there, under the proper conditions, 

 is the greatest growth of feeding-roots. 



The moisture of the soil in early spring is general. As 

 evaporation takes place during the growing-season, the 

 upper portions of the soil dry first, and soon the pasture- 

 region of the roots contains water far less than the capacity 

 for saturation of the soil. The rains in June, July, and 

 August, seldom are sufficient to saturate below the upper 

 few inches of the soil ; and generally, during these months, 

 atmospheric water is retained within the upper five inches of 

 the soil. 



