i6o RESEARCHES ON FUNGI 



Let us now consider what happens when, in a single horse-dung 

 ball, (1) only one spore germinates and (2) one hundred spores 

 germinate. 



(1) In Fig. 90 at A, as shown diagrammatically, there is a single 

 spore in the middle of a small horse-dung ball. At B the spore has 

 germinated and has formed a young mycelium which is growing 

 outwards radially in all directions. At C the myceUum is older 

 and now resembles the mycelium in Fig. 88 : it has become diploid 

 and hyphal fusions are taking place. At D the mycelium has 

 penetrated to the exterior of the dung-ball and is now a highly 

 complex diploid three-dimensional network. Moreover, it has 

 formed a single fruit-body which as yet is only partially developed. 

 Only one maturing fruit-body is shown at T> because, as we have 

 seen, a fruit-body of C. sterquilinus is so large that it often drains 

 and completely exhausts all the mycelium in a single horse-dung 

 ball.i 



What is happening to the fungus shown in Fig. 90, D ? The 

 fruit-body is growing at the expense of the cell-contents of all the 

 hyphae of the mycelium. In other words, the contents of the 

 mycelium are flowing toward the fruit-body from all parts of the 

 horse-dung ball. Obviously, this flow is aided by the hyphal 

 bridges which everywhere connect adjacent radial hyphae. Without 

 the aid of these bridges the conduction to the fruit-body of the 

 materials which are required for its growth would be a very slow 

 and round-about process. Taking this for granted, it is easy to 

 perceive that the significance of the hyphal fusions lies in part in 

 the production of bridges which enable short cuts to be taken by 

 materials flowing from the mycelium to the developing fruit-body. 

 It has already been pointed out that the hyphal fusions in Coprinus 

 sterquilinus have nothing to do with sex. We now see that they 

 have a beautiful significance in connexion with the transfer of food 

 materials from one place to another. It matters not at what 

 particular spot on the exterior of the dung-ball the fruit-body 



1 The mycelium in any dung-ball like that represented in Fig. 90, D, always 

 produces many minute fruit-body rudiments at the surface of the dung ; but, as 

 a rule, only one of these develops into a mature fruit-body, wliile the others all 

 suffer abortion. For the sake of simplicity, aborted rudimentary fruit-bodies are 

 not shown in Fig. 90, D. 



