GllKEN COLOUll, 75 



the same shape which the ovum had at its 

 formation, the rudiments of the stigma also 

 remaining unaltered." 



The sketches here given will convey to the 

 reader a correct idea of the form assumed hy 

 the grain when occupied by this fungus. The 

 dark green colour of the infected grains is 

 merely a common effect of the presence of the 

 mycelium of fungi. Mr. Berkeley, in a note to 

 his masterly paper in the Journal of the Horti- 

 cultural Society on the disease of the potato, 

 remarks — " It is well known that the presence 

 of the mycelium of fungi acts as a stimulant to 

 the chlorophyl : witness the rich tint of fairy 

 rings. A curious instance has, within a few 

 days, fallen under my notice. The hazel leaves, 

 a week or two back, were very generally spotted 

 with dark patches of green. On examination, 

 it was found that the reverse of such patches 

 was covered with erysiphe guttata, which had 

 been living at the expense of the paler portions 

 of the leaf, while in the subjacent part the 

 chlorophyl had become of a deeper green." 

 The chlorophyl is the term applied by botanists 

 and vegetable physiologists to the green 

 colouring matter of leaves. 



The question whether the fine contents of the 



