52 



It must be borne in mind that selection must be kept up continuously, and that 

 reversion takes place more easily than improvement. It took but one season to 

 seriously injure Professor Blount's wheats, but it will be two or more years before 

 they have recovered from that injury. Hallett, in England, was able to make his cele- 

 brated pedigree wheat by selection, carried on through many years, but the same 

 wheat grown by the ordinary farmer under unfavorable conditions for a few years 

 without care has reverted to an ordinary sort of grain. 



The effect of climate is well illustrated by four specimens of wheat which are to be 

 seen in the collection of the Chemical Division. Two of these were from Oregon and 

 Dakota some years ago, and present the most extreme contrast which can be found 

 in this variable grain. One is light yellow, plump, and starchy, and shows on analy- 

 sis a very small per cent of albuminoids; the other is one of the small, hard, and 

 dark-colored spring wheats of Dakota, which are rich in albuminoids. Between 

 these stand two specimens from Colorado, which have been raised from seed similar 

 to the Oregon and Dakota wheat. They are scarcely distinguishable except by a 

 slight difference in color. The Colorado climate is such as to have modified these 

 two seed wheats, until after a few years' growth they are hardly distinguishable in 

 the kernel. 



All localities having widely different climates, soils, or other conditions produce 

 their peculiar varieties and modify those brought to them. 



The result of these tendencies to change and reversion from lack of care in seed 

 selection or other cause has led to the practice of change of seed among farmers. A 

 source is sought where either through greater care or more favorable conditions the 

 variety desired has been able to hold its own. Sometimes this change is rendered 

 necessa-ry by conditions which are beyond the power of man to modify. As an 

 example, No. 10 of Professor Blount's wheats, known as " Oregon Club," a white 

 variety from Oregon, has been deteriorating every year since it has been grown in 

 Colorado, whereas if the seed had been supplied every season directly from Oregon 

 the quality would have probably remained the same. In extension of this illustra- 

 tion the fact may be mentioned that the annual renewal of the seed from a desirable 

 and favorable source often makes it possible to raise cereals where otherwise climatic 

 conditions would render their cultivation impossible through rapid reversion. This 

 is particularly the case with extremes in latitude, the effect of which is not found so 

 much upon the composition of the crop as on the yield and size of the grain. In the 

 South, the warmer climate, together, of course, with poorer soil and cultivation in 

 many instances, reduces the yield. 



A typical American wheat of the best quality should have approxi- 

 mately the following composition : 



Weight of 100 kernels grams.. 3.85 



Moisture per cent.. 10. 60 



Albuminoids do 12.25 



Oil. do.... 1.75 



Indigestible fiber do 2.40 



Ash do 1. 75 



Digestible carbohydrates do 71.25 



Dry gluten do 10. 25 



Moist gluten do 26.50 



To bring ioto a comparative view the means of the data obtained for 

 American cereals exhibited at the World's Columbian Exposition, the 

 following general table is given containing the data above mentioned, 

 with the exception of those relating to rice, together with the approxi- 

 mate typical composition taken from the preceding pages : 



