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Till: number of fungi that attack our cultivated plants is almost as great as that 

 of the insect pests, and their attack's at certain times are even perhaps more 

 difficult to combat than those of insects. It is asserted bv many persons that 

 healthy plants are not attacked by fungi, that it is only in the case of a plant 

 being diseased that fungi can find in it a congenial habitat, and that they are not the cause 

 of the disease. 1 do not think that this can be proved. Doubtless plants in an unhealthy 

 condition are more liable to, and suffer more from the presence of, parasites than those in 

 robust health, and certain conditions of the atmosphere are favourable to the growth of 

 fungi, and detrimental to our plants. But very often when a plant is infested bv a fungus 

 it appears to be quite healthy until the attack has made considerable progress. Fungi 

 vary very much in appearance, front the ordinary Mushroom and Toadstool to minute and 

 very delicate moulds. The part of the fungus that we see is, as a rule, only that part 

 which is concerned in the reproduction of its species by means of spores, so that it 

 represents, to a certain extent, the flower of an ordinary plant, the real fungus being 

 composed of a number of fine root-like organs within the substance on which the fungus 

 is growing. For instance, in the case of the common Mushroom, the real plant is the 

 "spawn," and the umbrella-shaped Mushroom is only a spore-bearing organ, and may be 

 destroyed without any injury to the fungus. Thus in many cases a plant is infested by a 

 fungus without any si m~i of the attack' until some of these spore-bearing organs are pushed 

 through the leaf, stem, or whatever part is attacked, when the presence of the fungus is 

 noticed for the first time, and w hen it is often too late to do more than prevent the pest 

 from spreading bv dispersing its spores. Many fungi live only on dead matter; these are, 

 of course, perfectly harmless to living plants, though when found on a dead plant they are often 



