FUNGI AND MODERN AFFAIRS — RAMSBOTTOM 317 



houses which have been severely bombed are liable to have their timber 

 affected, but blasts have cracked water pipes with a consequent seepage 

 of water through the walls ; leaves and other rubbish have caused over- 

 flows which run down the walls; shelters have been constructed so 

 that ventilation and even watercourses have been interfered with ; ven- 

 tilation bricks have been stopped up to prevent entrance of gas; or 

 sandbags which became rain-sodden propped up against walls, often 

 over air bricks ; houses left unattended, with no heat and leaky roofs ; 

 water tanks and pipes bursting, water taps left running in requisi- 

 tioned buildings — all have played their part in bringing about a good 

 deal of unnecessary waste. Furthermore, there is need for some sci- 

 entific control over new housing plans or we shall have a repetition 

 of the troubles which affected whole building estates after the War of 

 1914-18. 



In addition to causing diseases of trees, microscopic fungi cause 

 disease not only of crops but also of wild plants. The most striking 

 point about the flora of bombed sites is the rapid appearance of special 

 fungus parasites, as for example Bremia lactucce on groundsel. The 

 idea that disease is a result of civilization is very attractive to some 

 minds — but is entirely false. 



Fungi are the main causal agents of disease in plants. The losses 

 in different crops vary normally from 2 to 50 percent; figures for 

 the United States for wheat, oats, and barley in 1935 due to rust alone 

 were estimated at 277, 185, and 53 million bushels respectively. There 

 are many ways of combating fungus attacks, the most obvious being 

 the use of fungicides. Much depends upon having a thorough knowl- 

 edge of the life history of the parasite as well as that of the host plant, 

 for then the fungus can be tackled at its most vulnerable stage. 



Some varieties or races of plants are immune to the strain of fungus 

 parasite common in the neighborhood, and much work has been done 

 in the attempt to breed immune races. But it is frequently overlooked 

 that there is often as much variation in the parsite as in the host. Thus 

 the problem of producing a wheat immune to black stem rust theoreti- 

 cally necessitates the building up of a resistance to 177 physiological 

 races, though, practically, only the local strains present in any one area 

 need be considered. 



Less than a century ago, when the parasitic nature of many diseases 

 was beginning to be suspected, fungi were thought to be responsible for 

 many human affections. This was a consequence of Schoenlein's dis- 

 covery in 1839 of the fungus causing favus, which was immediately 

 followed by Lagenbeck's describing the fungus of thrush, and soon 

 afterward by Gruby's description of ringworm. With the gradual 

 recognition of the predominance of bacterial diseases and the abundant 

 problems they presented, mycology, except for the obvious dermato- 

 phytosis and actinomycosis, has not received the attention due to it, 



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