13 



the window pane. Other fungi, not indeed of the special forms 

 of mould, are the "rust" or smut of cereal crops. The remain- 

 ing difficulty, after the discovery of the potato-mould, the Pe- 

 ronospora, was to understand the full process of its reproduction. 

 Winter, on theory fatal to the life of any ordinary form or germ 

 of the potato-fungus, only laid the chill of a brief interruption 

 on its devastatmg work. There must be, so botanists said, some 

 secret retreat of vitality, some conserving organ or seed, out of 

 which the Spring called the evil powers into activity again. The 

 riddle has just been read by Mr Smith, an English botanist of 

 some repute. 



In the stems and corrupting fragments of blighted potato 

 plants, and under the dissolving influence of the Autumn rains, 

 very small brown grains or spheres have been found, developed 

 on the mould-threads just as these are ready to die by frost. 

 This is the preparation of the parasite for Winter. Everything 

 else perishes. The mould and its dead host, the potato, crum- 

 ble away. The little spheres, only the thousandth of an inch in 

 diameter survive, waiting patiently in the frozen ground. In the 

 spring they thaw and sprout, taking possession of other plants 

 in the same soil. The microscopist I have named is the first to 

 detect and expose this wonderful resource of the short lived but 

 destructive mould. It now becomes possible intelligently to 

 press to extermination this pest, as others, like the vine mould 

 and the wheat rust have had their ravages curbed before. 



This instance may stand for many, all teaching the same les- 

 son. Even the most refined investigations of science may have 

 their practical value. The steel-maker has found a help in the 

 "bright lines" of the spectroscope, and a jury searching for blood- 

 stains have learned to interpret its "absorption bands." So the 

 farmer of the future will, in common with all earth's workers, 

 subsidize science for protection and defence. 



