spore Distribution 



publicly exhibited. It would be a good thing if 

 judges rigidly disqualified such diseased plants.) 

 Refuse and manure heaps may harbour them, or 

 packages which have been in contact with diseased 

 plants may spread the spores. Seed (in the 

 gardener's, less often in the botanist's, sense) may 

 contain them ; or the fungus itself, or its spores may 

 adhere to the seeds, and so on. Even particles of 

 soU, as, e.g., from a " club "-stricken cabbage-patch, 

 may spread the fungus to other and hitherto healthy 

 gardens. 



Perhaps to f oUow the history of a familiar fungus 

 is the best way of gaining a clear idea of its way of 

 life. The rose mildew is perhaps as famUiar as any, 

 at any rate to country dwellers. The mealy white 

 covering which betokens the attack on shoots and 

 leaves, and later the felted mass of myceUum which 

 encircles the young shoots or forms wide patches 

 upon them, are far too common for the pleasure of 

 the gardener. This felt is so conspicuous because 

 the mycelium is formed wholly outside the plant 

 (the case only in the mildews), merely sending 

 minute suckers into its host to absorb its sap. This 

 robbery results in the shrivelling of the cells attacked 

 in consequence of the loss, and the leaves fail to 

 expand properly, so that food-making is interfered 

 with. Some cells may actually be killed outright, 

 and brown patches result. The mycelium has 

 grown from a spore which germinated where it fell 



44 



