14 T. A. Coward — Presidential Address 



and throw good top-dressing to the surface? In short we 

 must remember that those creatures which appear to be of 

 service by destroying pests do not discriminate ; they also 

 destroy other useful checks on these same pests. The bud- 

 destroying bullfinch eats also the seeds of troublesome weeds, 

 the tit kills the spider which itself ensnares alike the trouble- 

 some fly and the parasite which keeps it in check, the moth, 

 parent of the caterpillar, and the ichneumon which destroys 

 the grub. It is all very complicated, very confusing. All the 

 more reason for careful, unbiassed study of all animal life ; 

 we never know where and when we may hit on fresh light, a 

 new link in this complicated, tangled chain of nature. 



Without entering into the ethics of war, we can look back 

 and review the lessons of the recent struggle, when interference 

 with Nature was rampant. First consider food shortage apart 

 from political and economic causes ; it was deemed necessary 

 to encourage internal resources ; we strove to increase our food 

 supply, especially of wheat, potatoes and vegetables. We 

 sowed wheat everyw'here, but we did not always reap the 

 harvest; in certain soils, for long unsuited to or at least unused 

 to this crop, the wheat-bulb fly appeared and worked its 

 wicked will. It was not, as our late member. Dr. A. D. Imms, 

 pointed out, that Hylemyia coarctata was a new comer to our 

 lands, but that wheat had been sown on unfavourable ground, 

 following in incorrect rotation ; we were, in fact, very ignorant 

 about the life history of this fly, and unwittingly gave it an 

 opportunity of increasing before its natural parasites had a 

 chance of reducing its numbers to the normal. With a little 

 more knowledge we should have avoided the catastrophe ; but 

 had we continued to grow wheat in spite of the set-back, we 

 should probablv have discovered that we had in time reached 

 an artificial natural balance, when Man would have got some 

 wheat, but neither would the bulb-fly nor its parasites have 

 entirely vanished. We may, in cultivation, force the pace, 

 we do it constantly, but ultimately natural forces assert them- 

 selves ; a stable condition is reached. 



Game preservation has wrought many changes in Nature's 

 balance, and these are often closely connected with the intro- 

 duction of alien creatures. A new and complex situation 

 arose during the war; its effect is still noticeable. Apart from 

 the previous interference with animal life caused by game 

 preservation methods was the fact that a large number of men 

 were engaged in continuous efforts to decrease the numbers 

 of certain creatures, called by them " vermin," and simulta- 

 neously to increase the head of game, a persistent effort to 



