188 TILLERS OF THE GROUND CHAP. 



diseases as potato disease or the vine disease have 

 brought, but these are diseases which have 

 appeared suddenly, like the dreadful epidemics of 

 plague or cholera which sometimes sweep over a 

 country. Wheat-rust has been with man probably 

 ever since he began to cultivate wheat. Sometimes 

 it appears in a very bad form, and is then especially 

 destructive, but it is always present to a greater or 

 less degree. Perhaps some one then may ask, Does 

 it really do much harm ? Is it worth all the 

 botanists' toil to find out the cause and the cure ? 

 Here are two sets of numbers which may help to 

 answer this question. 



In Australia a great deal of wheat is grown. 

 In that country there are now nearly four million 

 people. It is estimated that there the annual 

 yearly money loss from wheat-rust is between two 

 and three million pounds. That is, every year, every 

 man, woman, and child in Australia, supposing 

 the loss to be equally divided, would lose between 

 ten and fifteen shillings from wheat-rust alone. In 

 Prussia in 1891, which was a very bad year for rust, 

 it was officially estimated that the loss to the com- 

 munity from the disease was twenty million pounds. 

 We can see from these figures that it is very well 

 worth while to try and find a cure for rust. Have 

 we not all cause to be grateful to the people who 

 have toiled to explain the why and the wherefore 



