THE SPHAEROBOLUS GUN 369 



(2) Infection of wood by glebal masses shot on to it from fruit- 

 bodies growing on a mass of dung. Here the mode of infection of a 

 piece of wood is as in (1), except for the fact that the fruit-bodies 

 from which the glebal masses are derived are situated not on another 

 piece of wood but on a mass of dung. 



Sphaerobolus, as already recorded, has been found on the dung 

 of elephants, horses, cows, hares, and rabbits ; and it is easily con- 

 ceivable that such animals as these, so well endowed with powers 

 of locomotion, serve to transport Sphaerobolus long distances and 

 often from one woodland area to another. For the sake of illustra- 

 tion, let us consider rabbits as possible agents for the transportation 

 of Sphaerobolus. Sphaerobolus fruit-bodies have been found on the 

 dung of rabbits in Germany and England x ; and there can be no 

 doubt that these animals, whilst feeding on herbage in fields and 

 woods, swallow glebal masses and that the spores or gemmae or 

 both pass down their alimentary canals unharmed and germinate in 

 their faeces. Rabbits are relatively small but active quadrupeds ; 

 and, where they occur, they are often very numerous. They leave 

 the little balls which make up their solid excreta scattered far and 

 wide upon the ground ; and, in woodlands, one can often see these 

 dung-balls lying in contact with fallen twigs and sticks, on logs, 

 and at the foot, or even on the top, of stumps. When fruit-bodies 

 are produced on rabbit dung, as they certainly are sometimes, it is 

 conceivable that the glebal masses shot from the Sphaerobolus guns 

 may land on adjacent sticks or stumps and that such discharged 

 glebal masses may germinate and cause an infection of the underlying 

 woody substratum. 



If discharged glebal masses serve to transfer Sphaerobolus from 

 rabbit dung to wood, they may also serve to transfer Sphaerobolus 

 from cow dung, horse dung, elephant dung, etc., to wood. 



(3) Infection of wood by mycelium growing on to it from infected 



dung. There is no difficulty in imagining that Sphaerobolus should 



begin its growth in the dung of hares, rabbits, cows, etc., from spores 



or gemmae derived from glebal masses swallowed by the animals 



concerned and that the mycelium so produced should spread from 



the dung to a stick or a stump lying beneath. The mycelium of 



1 Vide supra, pp. 350-351. 

 vol. v. 2 b 



