76 DISEASE IN PLANTS. 



First I must remind you that wheat {Triticuin) 

 differs from rye {Secale) in several marked charac- 

 ters, such as the breadth and shape of the glumes, 

 the number of flowers in the spikelet, etc. ; and 

 that the cultivated rye differs from cultivated 

 wheats in the characters of the straw, in having 

 long ears, and in its flowering glumes remaining 

 widely divaricated for some days when in flower. 



In 1888 Rimpau removed the young stamens 

 from the German wheat referred to, and pollinated 

 the stigmas with pollen from a long-eared rye. 

 Four sound grains were obtained, looking like 

 wheat-grains. 



The history of one of these grains was as 

 follows: In 1889 it yielded ears which were 

 peculiarly narrow and long, and its stalks were 

 also much longer than the wheat : the flowers 

 remained exposed, with widely open paleae, for 

 several days, and the grains were very peculiar, 

 though wheat-like. 



Fifteen of the best grains were selected, and 

 in 1890 three of the resulting plants proved to 

 be a wheat of the Square-head type and one quite 

 sterile. The others retained the elongated, narrow, 

 brownish-red ears, the flowering glumes again 

 opening wide for some days. This last is a 

 characteristic of rye, but not of wheat. 



A long series of natural hybrids of wheat, 

 barley, and oats are also described and discussed 

 by Rimpau, as well as artificial crosses some 

 very remarkable of barleys, but they must be 

 passed over here. 



