A Leaf Spot op the Pea-Nut or Monkey-Nut Plant. 529 



of the fungus ramifies primarily in the air spaces between the cell 

 tissue, and gives out sucking organs into the cells through which the 

 fungus draws nourishment from the cells and ultimately kills them. 



The attacked leaves die early and shrivel up or fall ; a field badly 

 infected presents a gloomy spectacle of plants, showing only a few 

 newly formed leaves, the remainder being dead and shrivelled up, 

 while some plants are in great part quite leafless. 



When the fungus has killed a smaller or larger area of the plant 

 tissues, it liegins to sliow signs of fructifying, and forms in the black 



FiG. 2 (Highly MaKnifial). — Spores ot tlic Fungus and showing 

 some which Gorminaf(.'(l in Water. 



nreas small dark dots or specks about the size of a pin-point and more 

 or less concentrically arranged. 



These dots are due to a cluster of fungal threads which break 

 through the epidermis of the plant, and whose function is to form 

 the spores of the fungus, and thus, much to the annoyance of the 

 agriculturist, to ensure the spread and perpetuation of the disease. 



The spore-bearing layer which thus breaks through the 

 epidermis forms elongated, light-coloured. 1-5 celled spores (fig. 2), 



