Lecture IX — 135 — Structure 



under influence of infestation becomes monarch : the phloem area be- 

 comes reduced while the xylem area is proportionately increased, 

 suggesting an increased water intake through fungal influence. But 

 Hatch (1937, p. 131) says that in pure culture, short-roots of Pinus 

 Strobus are monarch in vascular structure, and the reduction in 

 stelar tissues is accordingly not due to invasion by the endophyte. In 

 holosaprophytes (Johow, 1889), the vascular portion is always much 

 reduced, or xylem and phloem are diversely arranged. The stele is 

 much reduced in J uncus Tenageia following infection (Grutter, 

 1886). Later researches will have to determine further the influence 

 of endophytism on stelar anatomy. 



