124 PHYSIOLOGY AND NATIONAL NEEDS 



long been current in entomological circles with 

 regard to the ability of weevils to withstand almost 

 any amount of absence of ventilation, and, on the 

 other hand, a very natural prejudice exists in the 

 trade itself in favour of ventilation to prevent the 

 grain from heating — reasonable in so far as it recog- 

 nises that ventilation serves to carry off heat and 

 moisture, but leaving out of account other con- 

 siderations of much greater moment. 



As to the alleged capacity of grain-insects to live 

 and flourish without ventilation the most precise 

 statements have been furnished by one scientific 

 writer. He tells us that " a non- ventilated atmo- 

 sphere at about 80° F., charged with water vapour 

 (no matter how poor in oxygen, and contaminated 

 with carbonic acid gas), provides the most favour- 

 able conditions for the life and reproduction of these 

 weevils . ' ' Again : ' ^ Hence almost any accumulation 

 of CO2 in the atmosphere in which the weevils are 

 living may be disregarded as a preventive agent " ; 

 and, once more : "In the face of these and my other 

 results it would be absurd to hold either that weevils 

 require a free play of air, or even that free access to 

 air, when possible, is favourable to their existence.*' 

 In face of such statements as these, how could any 

 one feel much confidence in recommending air-tight 

 storage as a prevention of weevilling ? 



It was obviously necessary that the matter 

 should be set at rest once for all by a series of 



