296 RESEARCHES ON FUNGI 



quite distinct from the gemmae : he states that they do not germi- 

 nate either inside the glebal mass or when placed in culture media, 

 and he insists that their function is entirely unknown. 



The fatty mass making up the core of the projectile comes into 

 existence as the tramal cells and basidia break down and disappear 

 whilst the gleba is ripening. That the sticky substance does con- 

 sist mostly of fat is indicated by the following observations : (1) oily- 

 looking globules appear in the gleba as the tramal plates break 

 down ; (2) the substance is insoluble in water but readily dissolves 

 in ether, chloroform, xylol, or absolute alcohol ; and (3) the sub- 

 stance takes on a bright orange-red colour with the well-known fat- 

 staining reagent Sudan III. 



If with a freshly-discharged glebal mass one makes a smear on 

 a glass slide and observes it with the microscope, the spores are seen 

 to be immobilised by the solid fat in which they are embedded. 

 However, as soon as one adds to the smear a drop of ether or 

 chloroform, the matrix of the smear disappears and the tens of 

 thousands of spores are all liberated so that they float about freely in 

 the currents of the reagent. 



After the projectile has been discharged and has become exposed 

 to the atmosphere, it dries and shrinks somewhat, it becomes harder 

 and tougher, and it sticks very tightly to any object which it may 

 have struck ; but, even in the course of some years, it never becomes 

 brittle but retains its elastic hard-glue-like consistence. The 

 elasticity of old dry glebal masses can readily be demonstrated by 

 pressing them down with a knife-blade and then setting them free 

 again. 



Evidence of the adhesiveness of the Sphaerobolus projectile, 

 which is an important factor in the dispersal of Sphaerobolus 

 species under natural conditions, is provided by the following facts. 

 (1) When a projectile is shot against the side of a bell-jar or other 

 container in the laboratory, it sticks where it strikes, mechanical 

 force is required to dislodge it and, if left undisturbed, it remains in 

 the position it has taken up indefinitely. (2) When a projectile is 

 discharged in the open and happens to strike a leaf or a stem of a 

 grass or other flowering plant, it sticks where it strikes and, despite 

 wind and rain, as I have actually observed, remains in situ for some 



