FRUITING OF MOLDS 



19 



it becomes a ball of considerable size, at first white, but 



finally black, and large enough to be seen with the naked 



eye (Fig. 7). Inside of this ball the living substance of 



the plant soon breaks up into hundreds of minute bodies 



(P^S- 7)- These are the spores, and after they have 



become formed the sacs which hold them (sporangia) burst 



and the little spores are thrown out to be blown about 



by the wind. 



These molds 



are at first soft 



and white, but 



later bl^ck from 



the abundance 



of these spore 



sacs. 



Another very 

 common sort of 

 mold fruits still 

 differently (As- 

 pergillus). A 

 fine, threadlike ^'^- 8- 

 mycelium is 

 produced, as in 

 the other cases, and from it grow the fruiting branches. 

 At the end of each fruiting branch grows a little round 

 ball, from all sides of which project many little knobs 

 (Fig. 8, a). These knobs lengthen a little, but soon break 

 up into round spores very much like the branches of blue 

 mold (Fig. 8, a'-c). The result is that, since they pro- 

 trude in all directions, there appears on the end of each 

 fruiting branch a little rounded mass, looking very much 



A colony of Aspergillus, showing mycelium 

 and spore clusters. The iDwer figures show in 

 detail the method of spore formation. 



