LEGISLATION AND DISEASE 229 



Finally, it is more than doubtful whether diseases are 

 mainly introduced into a new country through the ordinary 

 channels of trade. It is directly opposed to common 

 experience, also to careful investigation, to conclude that 

 diseased plants are sent out by nurserymen. 



In these days of rapid transit numerous small packages 

 containing seeds, which may have fungus spores adhering, 

 or a few potatoes, which may possibly contain mycelium 

 of the fungus causing potato blight or leaf-curl in their 

 substance, are being constantly sent to friends residing 

 abroad, and by such means diseases are disseminated in a 

 way well outside practical legislation. 



In discussing the spread of disease from an infected 

 area to another adjoining area, or, in other words, from 

 one part of a country to another, the subject has to be 

 viewed from a different standpoint to that followed up to 

 the present. New factors of importance have to be con- 

 sidered, as the dispersion of spores by wind, animals, 

 insects, and perhaps most of all through human agency. 

 The constant interchange of seed grown in different districts, 

 etc., favours the dispersion of disease. These all lie out- 

 side the sphere of legislation, and unfortunately, it must 

 be admitted, also often outside the sphere of preventive 

 measures that can be applied by the practical man. It is 

 in this connection that spraying is of real service in check- 

 ing the spread of a disease, and if used in the sense of 

 a preventive rather than as a cure, beneficial results will 

 follow. 



The only remaining point requiring notice, perhaps the 

 most fruitful of all in disseminating disease to surrounding 

 areas, is neglected gardens and orchards, which in this 

 country are far too abundant. Such places become in 



