438 INJURIOUS INSECTS AND FUNGI. [March 1896. 



The following figures, drawn by Mr. Worthington Smith, 

 illustrate Rhizodonia violacea. 



Fig. 1. 



Piece of outside of potato with patches of Wiizoctonia violacea, Tul. Natural size. 



The above figure shows a piece of the outside of a potato 

 with the fungus upon it in patches. Very frequently these 

 patches ore close to an " eye," through which the mycelium 

 enters, as well as through the skin. These patches consist of 

 tiny perithecia with fringes, or " webs," so that the fungus is 

 sometimes called the copper web." 



These perithecia are shown enlarged and in section below. 



Fig. 2. 



Rhizoctonia violacea ^ Tul. 



A. — Enlarged 5 diameters. 



B. — Enlarged 30 diameters. 



C. — Section through peridium. 



The functions of th(5se perithecia and their relation to the 

 mycelium are not clear. Tulasne is not very definite concerning 

 them, and terms them corps miliares. Prillieux believes that 



