156 



METHODS OF CORN BREEDING. 



x\t the Association ot American Agricultural Colleges and Experi- 

 ment Stations last October, Dr. Hopkins of the Illinois Experiment 

 Station read a paper on this subject which was of special interest. 



Some experiments have been made in Jamaica by Mr, Palache, one 

 of the Instructors of the Agricultural Society and by Mr. Barclay, 

 the Secretary , in the selection for seed of the finest ears and the 

 largest grains, but nothing has been done on the lines indicated by 

 Dr. Hopkins, — selection by examination of the grain. 



He points out a grain of corn is not uniform all through, that there 

 are three distinct parts which may be readily observed by cutting the 

 grain across with a penknife, and that these parts differ in their chemi- 

 cal composition and their value as food for either man or stock. 



These three parts are : 



(1) The dark coloured and rather hard and horny layer lying next 



the hull principally in the edges and towards the tip end 

 of the grain. 



(2) The white starchy-looking part near the crown end of the grain. 



(3) The germ which occupies the central part of the grain toward 



the tip end. 

 The illustration-* shows two grains cut across : 



I r A has more of the horny part in proportion to starch and also a 

 larger germ than B. 



The horny layer which usually constitutes about 65 per cent, of the 

 corn grain contains a large proportion of the total protein in the grain. 



The white, starchy part constitutes about 20 per cent, of the whole 

 grain, and contains a small proportion of the total protein. The germ 

 constitutes only about 10 per cent, of the corn grain ; but, while it is 

 rich in protein, it also contains more than 85 per cent, of the total oil 

 content of the whole grain, the remainder of the oil being distributed 

 in all of the other parts. 



By keeping in mind that the horny layer is large in proportion and 

 also quite rich in protein, and that the germ, although rather small 

 in proportion is very rich in protein, so that these two parts contain a 

 very large proportion of the total protein in the corn grain, it will be 

 readily seen that by selecting ears whose grains contain more than 

 the average proportion of germ and horny layer we are really select- 

 ing ears which are above the average in their protein content. As a 

 matter of fact, the method is even more simple than this, because the 

 •white starchy part is approximately the complement of, and varies in- 

 versely as, the sum of the other constituents ; and tu pick out seed 

 corn of high protein content it is only necessary to select those ears 



*Clich6 lent by Dr. Morris, Commissioner __Imperial Department of Agriculture. 



