58 EFFECT OF SUNSHINE. 



acquainted with the distinctive character of the 

 uredo by the aid of the microscope, while the 

 vegetable physiologist is enabled to form an 

 opinion on its peculiar habits and modes of 

 growth. The real habits of this common 

 disease of the wheat-plant, are no longer veiled 

 by inaccurate observations, or popular imagina- 

 tions. The mystery is cleared up, and the 

 cultivator who has often witnessed the discolor- 

 ation of his crops by this fungus, without any 

 real knowledge of its nature, may now become 

 thoroughly acquainted with the object of his 

 frequent surprise and annoyance. 



Very often, as happened in the spring of 

 1843, and in that of the present year, 1846, 

 the corn-fields have seemed quite to droop 

 under the influence of this parasite. The aspect 

 on such occasions is so sickly as to create serious 

 alarm. But the arrival of a few bright warm 

 days soon dissipates the evil. The genial 

 beams of the sun seem completely to vanquish 

 it, so that it disappears in an astonishing man- 

 ner, and a healthy greenness speedily succeeds 

 to the sear and yellow tints that have disheart- 

 ened the farmer. The fact is, that when the 

 sun dries up the superfluous moisture, the fun- 

 gus cannot spread, and health returns. It 



