648 THE FUNGI WHICH CAUSE PLANT DISEASE 



light on the inter-relation of the various species and their hosts. 

 Apple & Wollenweber '^ have made an extensive study of several 

 species to lay the ground for a monograph. They conclude that 

 in delimiting species important characters are the forms of the 

 conidia, especially their bases, apices, and degree of curvature and 

 septation (see Fig. 436); the color of the myceUum and spores; 

 the presence or absence of chlamydospores. They cast aside as 

 valueless many earlier descriptions substituting new diagnoses 

 and new names. According to their conception, the following 

 names should stand. 



F. solani (Mart.) Sacc. =Fusisporium solani Mart. =Fusarium 

 commutatum Sacc. 



F. martii A. & W. =Fusisporium solani Mart. 



F. coeruleum Lib. =Fusariimi solani. 



F. discolor A. & W. =Fusarium solani. 



F. rubiginosum A. & W. =Fusarium solani. 



F. discolor var. sulphureum (Schl.) A. & W. =Fusarium sul- 

 phureum Schlecht. 



F. subulatum A. & W. 



F. metachroum A. & W. 



F. orthoceras A. & W. =F. oxysponim Sm. & Sw. not Schl. 



F. theobromse A. & Struk. _-.«i— ^- 



F. wilkommii Lin. =F. bacilligerum B. & Br. 



F. falcatum A. & W. =F. vasinfectum pisi Schk. . ' "i 



F. gibbosum A. & W. 



It will be noted that several of the species mentioned below 

 are here involved. 



F. platani Mont. =Calonectria pyrochroa. See p. 205. 

 F. rubi Wint. 



Mycelium white, becoming pink, especially 



abundant on the flowers; conidia elongate, 1 



to 8-septate, variable in size and form, 



no. 437. -Section of ^*™sht or cuTved, 14-30 X 3-3.5 m, not con- 



ovary showing my- strlcted. 



pd and o^r^Aiter Cook '^' "' found this fungus in diseased 

 ^^°°^- buds of dewberries and by inoculation dem- 



onstrated that it is responsible for witches-broom, double- 

 blossom, and similar abnormal growths of this plant. 



