LEGISLATION AND DISEASE 221 



stroyed by the same kind of fungus attacking Verbenas in 

 Europe. These are a very few of the cases that could be 

 cited where European plants that have been cultivated in 

 distant parts of the world have been attacked there by the 

 same kind of fungus from which they suffer at home. 



A point of importance in connection with the above 

 examples is the fact that, in every instance, the introduc- 

 tion to a new country must necessarily have been by 

 means of seed. 



Next comes the question : How did these plants become 

 infected in the first instance in a new country, with the 

 same kind of fungus from which they had been accustomed 

 to suffer at home ? 



Two possible answers suggest themselves. Either the 

 fungus was previously present in the new country, and 

 happened to be growing in the immediate neighbourhood 

 where the introduced plants were first grown. Or, secondly, 

 the spores of the fungus were imported along with the seed, 

 adhering to its surface. 



The first supposition may be dismissed at once, as not 

 having a shred of evidence in its support. The latter 

 supposition is strongly supported by facts, and may with- 

 out doubt be accepted as the true solution. It has long 

 been known that smut and bunt in cereals are mainly 

 perpetuated by the spores of these fungi adhering to the 

 outside of the grain, and that by proper treatment the 

 spores can be destroyed, a practice commonly followed. 

 This method of treating seed before sowing could be 

 greatly extended with advantage. 



Packets of a dozen different kinds of seed purchased at 

 random were carefully examined in the Jodrell Laboratory 

 at Kew, and in four instances, spores of the fungus, well 



