BLIGHT. 19 



acre of good ground generally produced in England, in the thirteenth 

 century, only about twelve bushels of wheat and in the sixteenth from 

 sixteen to twenty bushels, and barley thirty-six bushels. Fifty years 

 ago the produce was twenty-two and a half bushels the acre. Since 

 this the amount has increased as all productions do increase by the 

 advance of people in knowledge and industry. 



The crops in the United States show an average vastly greater than, 

 this, and probably greater than in any other part of the world. In- 

 stances of extraordinary production are frequent, but the medium may 

 be estimated at about forty bushels the acre. The aggregate product of 

 the United States in 1842 was 102.317.540 bushels, being an increase 

 of 10 per cent., or 10.674.683 bushels on the previous year. 



When a distinguished Roman farmer was indicted and brought be- 

 fore an assembly of the people for sorcery in having produced larger 

 crops from a small spot of land than his neighbors from their extensive 

 fields, he answered the charge by producing his more efficient instru- 

 ments of husbandry, his vigorous oxen and his hale young daughter, 

 and said " these, Romans, are my instruments of witchcraft, but, I 

 cannot show you my labors, sweats, and anxious cares." 



The principle casualties to which wheat is liable are blight, smut 

 and mildew. By the first the fibres are contracted and enfeebled, and 

 the grain is deprived of sufficient nourishment. It was considered 

 among the Greeks and Romans a sign of the wrath of the offended dei- 

 ties, and no remedy was, of course, resorted to. By the second the 

 stem and ear are affected, and by the third the grains are filled with a 

 dark powder. But the two last are confounded, or they may be refer- 

 red to the same disorder at different periods of the plant's growth. 

 Three causes are assigned for these disorders ; viz. cold and frosty 

 winds, sultry and pestilential vapors and a parasitical fungus. The 

 first stops the current of juices, the leaves die and the vessels of the 

 plant become filled with insects. The second occurs after the growth 

 of the grain and commonly after heavy rains. Its effects are called 

 burnt grain and were thought contagious. The grain of mildewed 

 plants are said to answer for seed. Smut consists in the conversion of 

 the farina of the grain into a black sooty and offensive powder which, 

 under the microscope, shows millions of minute globules. It has been 

 attributed to a diseased state of the seed, but is now known to be a 

 fungus, (see blight.) 



BLIGHT pucinia c. 24, o. 9, T, 4, sp 30. P. graminis is the well 

 known blight, a minute parasitic fungus. In attacking the stem or 

 leaves of the grain-plants, or corn, it first has the appearance of orange 

 colored streaks, which afterwards take a deep brown color. The 

 plants attack the parenchyma just below the pores of the cuticle. 

 Each is so small that any pore on a straw will produce from 20 to 40 

 fungi and each of these will doubtless produce at least 100 reproduc- 



