LEGISLATION AND DISEASE 227 



a source of danger. Many kinds of foreign fruit examined 

 at Kew have furnished fungus spores which have germinated 

 readily, and which, if they had found their way to the 

 proper host-plant, would undoubtedly have established a 

 disease. One redeeming feature in this case lies in the 

 fact that the bulk of imported fruit is consumed in towns, 

 consequently the spores are not so likely to reach those 

 places where infection would result. 



Two of the most injurious and most widely distributed 

 diseases on ripe apples are ' Brown rot' (Monilia fructigena\ 

 and ' Apple scab ' (Fusicladium dendriticum). It is very 

 important to remember, however, that the spores from ripe 

 fruit are not the sole means of propagating these diseases. 

 Although fruit growers only recognise these as fruit 

 diseases, as a matter of fact, in both instances, the disease 

 first attacks the leaves, where its presence can only be 

 detected by an expert. The spores formed on the leaves 

 are washed by rain on to the young fruit, and in course of 

 time the disease shows itself under the form of scab or 

 brown rot. 



It is obvious that in these instances scab and brown rot 

 could be conveyed from one country to another quite as 

 readily on living trees as on ripe fruit. Furthermore, trees 

 conveying the disease need not necessarily bear leaves. If 

 a tree has suffered from disease, spores of the fungus are 

 washed by rain down the stem and branches, and remain 

 in cracks in the bark until the following spring, when they 

 germinate, and in many instances gain access to the leaves, 

 and infection results. 



It is mostly in connection with the importation of living 

 plants and fruit that legislation has been called in as a 

 safeguard, but, as will be seen from the above account, as 



