152 BIOLOGICAL PROBLEMS 



wet weather late in summer or in early autumn, 

 according to the county or season, conidia are washed 

 down through the soil to the surface of the tubers, 

 and can penetrate the skin, just as they can the green 

 leaves, and bring disease. In this way there is a 

 further loss to the crop through disease. It Avas said 

 many times last year that diseased potatoes do not 

 matter: they can be used to feed pigs. In 1845 

 diseased potatoes were used for potato flour, but the 

 quantity yielded by the diseased potatoes is less than 

 from sound potatoes, although the quality does not 

 appear to suffer the flour is a little darker in colour 

 but in no degree unwholesome. At a time like the 

 present we want the utmost return from our efforts: 

 from the figures published by the Commission for 

 the Relief of Belgium there is a difference between 

 the energy secured from a pound of European and 

 American potatoes in good condition, being 78 calories 

 in favour of the European, a difference equivalent in 

 caloric value to the energy obtainable from an egg of 

 medium size. If this is the case, there would surely 

 be a considerable loss in energy from an equal weight 

 of diseased potatoes, and the feeding value, even when 

 used for pigs, would be exceedingly low. From what 

 we have said, it will be seen that a man who has care- 

 fully and thoroughly sprayed may obtain disease 

 through the neglect of his neighbour, or a careful 

 community from that of one careless one. The more 

 disease is prevented from appearing the less risk there 

 is of serious loss. That is why we should aim at uni- 

 versal spraying, spraying the garden of the palace as 

 well as that of the humblest cottager. That is why, 

 last year, premier and peer, plotholder and peasant, 

 shouldered knapsack machines and learnt to spray. 



In a campaign many problems confront one: how are 

 we to reach all sections of the community, to provide 



