A STUDY OF WHEAT. 



be perfectly hereditary, and all the organs show the greatest 

 degree of variation. The fruit of one. variety is more than 

 2,000 times the size of the fruit of another variety. The 

 varieties of melon differ very much, some being as small as 

 plums, while others weigh as much as 66 pounds; one variety 

 has a scarlet fruit ; another is only an inch in diameter, but 

 is three feet long, and is coiled in a serpentine rnanner in all 

 directions ; the fruit, of one variety can scarcely be distin- 

 guished externally from cucumbers ; one Algerian variety sud- 

 denly splits up into sections when ripe. The cultivated vari- 

 eties of corn are descended from a single primitive wild form, 

 which has been cultivated in America for a long period. There 

 is at present a very wide difference between the cultivated 

 varieties and the primitive one, as well as a very great dif- 

 ference between the cultivated varieties. Some of the plants 

 are only 'one and one-half feet high, while others are 

 from fifteen to eighteen feet. The grains vary extremely in 

 form, size and number, while in color they vary from white, yellow, 

 red, orange, violet, streaked with black, blue, or copper-red. 

 There is even one variety of corn which has three different 



Fig. i. Cross Section of Dic/il Wheat. X 230. 



A, First Fruit Coat ; B, Second Fruit Coat ; C, Third Fruit Coat ; D, First Seed Coat ; 

 E, Second Seed Coat ; F, Albuminous Layer. Drawn with the Camera Lucida. 



kinds of fruit, differing in form, color and size, on one ear. 

 These illustrations are used only to show to what extent 

 the amount of deviation in the varieties of a primative form 

 may increase under cultivation. Wheat gives us just as fine 

 an illustration of the great variation in a vegetable form as 

 any of those already mentioned. The three different . spec 



