174 INSECT PESTS 



soil and in varying proportions. It is clear then that 

 what 18 poison to one may be rich provender for another. 

 This is where the question of manuring comes in. We 

 must judge, by making experiments or by utihzing the 

 experience of others, what proportions and what con- 

 stituents are necessary for each kind of crop. 



Originally the word ''manure" was simply" *' man- 

 oeuvre " and referred to tillage rather than to the feeding 

 of the soil. Shakespeare speaks somewhere of the mind 

 being " manured with industry," meaning the appHcation 

 of exercise, and not superphosphate, to the brain-pan. 



Minnehaha, the bride of Hiawatha, was the first Land 

 Girl. She used to scratch about the Httle crop of Indian 

 maize with a pointed stick because she found it improved 

 the growth. In that simple picture you have the begin- 

 ning of agriculture, so that the Land Girls of to-day have 

 merely gone back to their old love after all, and let us 

 give those early land girls credit in this, viz. that whereas 

 men first thought of killing, it was reserved for the women 

 to inaugurate the first of the arts of peace. 



But then, the mere working of the soil soon became 

 totally inadequate for the permanent raising of crops, as 

 was found to be the case in the Southern States before 

 the American Civil War. In fact that war itself was 

 caused simply because the settlers were too lazy to man- 

 ure their cotton plantations. When the land gave out 

 they just shifted on to virgin soil elsewhere, and thus came 

 at last into contact with their northern relations, bringing 

 their slaves with them. The northerners did not believe 

 in slavery, and the southerners did, and were determined 

 to keep them. Then the fun began. 



No, land is limited in area, very much so in England, 

 and we must always renew the store of plant food as we 

 go on from year to year. This is done by the well-known 

 rotation system, by which one crop indirectly provides 

 the food for the next, and also by adding manures. 

 Manures are of two kinds, organic and inorganic. The 



