408 



THE AVHEAT CIJLTOilST. 



of plants spring. The spores are borne along in 

 the wind, among the growing wheat ; and wherever 

 the straw is not perfectly liealthr, and able to resist the 

 attacks of snch parasitic fungus, the seeds adhere to the 

 diseased leaves and stems, germinate, grow, and tend to 

 destroy the crop. 



There are many kinds of mildew and rust, which 

 originate from spores. Fig. To represents a magni- 

 fied view of a small portion of what is scientihcally 

 called uredo riibigo vera^ in which the spores are repre- 

 sented with a sort of basket-work extending from one 

 to another. 



Smut m Wheat. 



The illnstration herewith given (Fig. 76) represents 

 a magnified view of what is scientifically known as 



livedo caries^ which is common 

 to wheat ; and seldom attacks 

 any other cereal plant. The 

 dark-colored excrescences rep- 

 resent the spores or seeds of 

 the uredo caries. Unlike other 

 maladies, this one takes its ori- 

 gin in the interior juices of the 

 wheat plant ; and afi'ects the 

 kernels, instead of the straw. 

 The pericarp of the kernels of 

 wheat contains a black mate- 

 ria. T6.-smut magnified. ^..^^^ greasy to the touch, in- 

 stead of flonr. The dust of caries, nnlike that of 

 smut, emits an unpleasant odor; and the nauseous 

 smell is sometimes perceived in wheat bread. The 

 semeniform grains of the caries (Fig. 76) attach them- 



