118 



FIG. 15. Diagrams elucidating conidial shape. 



longitudinal axis of the conidium. In diagrams I and II, Fig. 15, the 

 point of greatest diameter on the line a a' is midway between the base 

 and apex of the conidium; while in diagrams III and IV it is nearer to its 

 base. If the conidium tapers from the point of greatest thickness toward 

 each end a fusiform (Diagr. Ill) or elliptical (Diagr. I, 1, 2) conidium re- 

 sults. If for a sufficient distance on each side of the line a a' the conidium 

 remains of uniform diameter it approaches more nearly the form of a cyl- 

 inder (Diagr. II, 1, 2). When the maximum diameter is nearer to the base 

 than to the apex, somewhat rapid tapering gives a fusiform conidium (Diagr. 

 Ill) , but if (as in Diagr. IV) the diameter lessens very gradually, as from the 

 point a to point y, the conidium may be said to be subcylindrical. 



