no PHYSIOLOGY AND NATIONAL NEEDS 



involved were also of a chemical nature, quite 

 beyond the limits of my own capacity, and it became 

 necessary to secure the services of a properly trained 

 chemist. The generosity of the Eoyal Society 

 enabled me to do this, and I was fortunate enough 

 to find in my colleague, Mr. H. D. Elkington, the 

 right man for the purpose. I may say at once that 

 much of what I am able to tell you to-night is the 

 result of Mr. Elkington's enthusiastic co-operation. 



The dangers to which stored cereals are liable 

 may conveniently be classified under four heads,- 

 (1) the attacks of rats and mice, (2) the attacks of 

 insects and mites, (3) the attacks of moulds and 

 bacteria, and (4) the process known to the trade as 

 '' Heating." 



As to the rats and mice I need say nothing. The 

 danger from this source is completely eliminated 

 by any rational method of storage, and though the 

 loss in this connection is undoubtedly still enormous, 

 its prevention would seem to be a matter for legisla- 

 tion rather than for scientific investigation. 



Of the insects, on the other hand, I might say 

 much, for there are many different kinds involved 

 in the problem and on each one a volume might be 

 written. The best-known and the most destructive, 

 at any rate in temperate climates, are the grain 

 weevils, Calandra oryzae and Calandra granaria, but 

 in India two other beetles, Rhizopertha dominica 

 and Trogoderma khapra, are also very serious pests. 



