E. J. BUTLER 17 



experiences in this direction, but it is unnecessary to labour what probably all 

 mycologists would consider a well-known fact. 



Of cases where the imj^ortatiou of plants lias been followed by the 

 appearance of fungi conveyed by them to a new locality there are niany. None 

 are of greater interest than those disclosed by an enumeration of the fungus 

 flora of the great botanic gardens, such as those of Kew and Beilin. In these 

 gardens a number of foreign species appear from time to time and are unques- 

 tionably introduced on plants purchased or presented from abroad and on their 

 packings. Kew, for instance, has a much larger recorded fun.gus flora than 

 any other area of its size in the world. In the same way parasitic fungi are 

 introduced with foreign varieties of plants by experimental farms and 

 departments of agriculture. In Australia two grass rusts appeared for the first 

 time on the young plants grown from seed imported by the Victoria Depart- 

 ment of Agriculture from the United States. ^ In India the only occasion 

 on which the crown rust of oats has been seen was at Pusa, shortly after the 

 experiment farm was started and when Canadian oats were being tried. The 

 race of the parasite Melamj)Sora Lini which grows on cultivated flax has also 

 only once been recorded in India, on an experimental crop of recent introduc- 

 tion in the Nilgiris, while, on the other hand, the race of the same parasite 

 which grows on the botanically allied linseed and which is common in India, 

 is said to have reached Australia with seed from Calcutta.^ Nurseries and 

 florists' establishments must have played a considerable part in dissemina- 

 ting fungi of all sorts, from the very nature of their trad?. Settlers, 

 planters, and missionaries have doubtless also been responsible at times for 

 the introduction of fungi on imported plants and other agricultural 

 produce. * 



It is, however, when we come to consider tlie spread of specific diseases 

 of economic plants, that the close connection between their movements and 

 those of the living plants on which they are borne becomes most evident. 

 Many instances will be fouiid in the detailed list below and only a few need 

 be referred to here. 



The group of vine diseases of North American origin, the appearance 

 of which was the outstanding featuie of the history of viticulture 

 in Europe during the nineteenth century, followed on the 

 shortening of the voyage between the two continents due to 

 the introduction of steamships, and two of the worst, the mildew 



' McAlpine, D. " Rusts of Australia," 1906, p. 43. 

 2 Agrk. Gaz. New South Wales. II, 1S92, p. 157. 



