Small and Bush Fruits: Gooseberries 149 



America. As the mildew is a native of the United States, this statement 

 may be quite true, but it lacks evidence. It has also been stated that the 

 mildew came to England from the Continent, but out of a batch of standard 

 Gooseberry bushes imported at the same time, only one showed a little 

 mildew, and that only after it had been in this country for some time, so 

 that the evidence is not convincing. The batch of Gooseberries in the 

 Evesham district, where the mildew was first observed ~in~ England, were 

 not imported, but raised on the spot. In the United States the mildew is 

 not uncommon on the native Gooseberries, but does not assume the propor- 

 tions of an epidemic; but it attacks European species so virulently that 



they cannot be cultivated at a profit. 

 The mildew has also been met with 

 sparingly on Black and Red Currants 

 in this country. There is nothing 

 unusual in the behaviour of American 

 Gooseberry Mildew. Epidemics, that 



i s severe outbreaks of a disease, are 



4.- n i 

 practically unknown, except under 



very exceptional circumstances, among 

 the indigenous plants of any country. 

 Such have grown along with the para- 

 sitic fungi, also indigenous, for such 

 a long time, that they have become 

 accustomed to each other, and neither 

 can take any great advantage of the 

 other. On the other hand, when you 

 introduce a plant into a new district, 

 it often suffers severely for a time. 

 The same is true when a parasitic 

 fungus invades a new country, as in 

 the present instance; at first it simply 

 runs riot with those plants it can attack, but gradually loses its virulence. 

 When the Hollyhock Rust first invaded this country, it rendered the 

 cultivation of Hollyhocks practically impossible for a time. The rust is 

 yet with us, and will probably remain, but it has found its level, and 

 Hollyhocks are grown in abundance. (See Vol. II, p. 54.) 



The American Gooseberry Mildew first attacks the tips of the young 

 shoots, rarely extending backwards for more than a few inches; it soon 

 afterwards appears on the fruit. It first appears as a pure-white, thin 

 mildew, much resembling in general appearance the European Gooseberry 

 Mildew. The mildew soon becomes powdery, due to the formation of 

 summer spores, which are scattered by wind, birds, insects, &c., and infect 

 adjoining plants, on which the mildew soon appears and produces summer 

 spores, which infect other plants, and thus the disease spreads with 

 great rapidity unless promptly checked. Soon after the summer spores 

 have been scattered, the mildew changes to a dull-brown colour, and be- 



Fig. 375. American Gooseberry Mildew. Appear- 

 ance of afflicted shoots in September 



