CONCLUSION 181 



gingerbread of his profits long before any pest appears 

 on the scene. I find, too, that this is quite a common 

 view of farmers and growers in relation to pests. They 

 say, " Yes, but you can't spend that amount of money, 

 or devote that amount of labour, on fighting pests. The 

 pests had better by half take what they want and go." 

 Precisely, although the question of artificial remedies 

 becomes a more practical possibility to the small culti- 

 vator and the allotment worker. Yet in all cases readers 

 will find that I recommend them to look at the thing from 

 an economical standpoint, and above all to examine the 

 life-history for themselves and to seek out the natural 

 remedy or method of control, which latter I have always 

 emphasized the importance of. 



Now the question of pests as a whole is only one small 

 section of the vast and universal subject of parasitism. 

 It will be remembered that I have described how pests 

 have constantly appeared to be invested with the actual 

 power to determine the continuance or not of a species 

 on the earth, at least to determine its change of form. 

 This may not be actually so, although readers of that 

 thoughtful book. Mosquito or Man, wherein are recorded 

 the researches of Sir David Bruce and others in Nigeria, 

 will see that there is something more than mere surmise 

 in such a suggestion. 



We have spoken of the ubiquity and resourcefulness 

 of pests, and have seen in the case of the liverfluke in 

 Chapter II the extraordinary expedients by which they 

 manage to secure a place in life for their progeny. We 

 have almost as good an example in the case of the Com- 

 mon Tapeworm {Tcenia solium) which forms such a strange 

 hnk between human beings and the Pig. The repugnance 

 of eastern nations to the eating of pork and the flesh of 

 other " unclean " animals is more than a religious ordin- 

 ance. It arose from a correct estimate of the penalty 

 often paid for partaking of an unnatural food. After all 

 said and done, we were meant to be vegetable and fruit- 



