368 RESEARCHES ON FUNGI 



First of all, it must be realised that, since the spores and gemmae 

 in a discharged glebal mass cannot escape into the air owing to their 

 being imprisoned in the gleba's glutinous matrix, a piece of wood 

 cannot be infected by means of wind-blown spores or gemmae. 



It must also be realised that, since a glebal mass, after discharge, 

 sticks so tightly to whatever it has struck or fallen upon that it 

 cannot be dislodged by the wind, a piece of wood cannot be infected 

 by means of wind-blown glebal masses. 



There appear to be at least four possible ways in which a piece 

 of wood may become infected with Sphaerobolus : ( 1 ) by one or more 

 glebal masses being shot on to it from fruit-bodies growing on 

 another piece of wood, (2) by one or more glebal masses being shot on 

 to it from fruit-bodies growing on a mass of dung, (3) by mycelium 

 growing on to it from infected dung, and (4) by spores or possibly 

 gemmae which have passed through the alimentary canal of some 

 herbivorous animal. Let us consider these possibilities seriatim. 



(1) Injection of wood by glebal masses shot on to it from fruit-bodies 

 growing on another piece of wood. When a piece of wood happens 

 to lie within about 20 feet of another piece of wood which bears 

 Sphaerobolus fruit-bodies, it is within range of Sphaerobolus guns 

 and glebal masses may fall upon it. We know that a glebal mass 

 placed in water readily germinates as a whole owing to the fact that 

 its gemmae send out radially a vigorous clamp-connexion-bearing 

 mycelium. Therefore, if a piece of wood, not already occupied by 

 another wood-destroying fungus and otherwise suitable as a sub- 

 stratum for Sphaerobolus, has one or more glebal masses shot on to 

 it from fruit-bodies situated on a neighbouring piece of wood, there 

 seems no reason why it should not become infected with Sphaerobolus 

 as soon as ever the weather becomes sufficiently moist for the glebal 

 mass or masses to germinate. In forests, probably, sticks and other 

 masses of wood often become infected with Sphaerobolus by this 

 very means. However, while the discharge of glebal masses from 

 one motionless piece of wood to another may well provide for a 

 slow and local spread of the fungus in particular woods, it does not 

 account for the transportation of the fungus from one piece of wood 

 to another piece of wood far distant from it nor for the spread of 

 the fungus from one woodland area to another. 



