134 TEANSACTIONS OF THE ILLINOIS 



young plums fall from the trees before maturing, simply because the 

 ovaries, the seed germs, have not been fertilized (or pollenized, which 

 I think is the better word). It is probably true that the plum cur- 

 culio laid one or more eggs in every one of them, but nevertheless 

 the fruit would have matured into good, marketable plums, if the 

 stigmas had received and sent down to the ovaries acceptable, potent 

 pollen. I can say, and tell the truth, that I have marketed a Miner 

 plum that had on it eighteen ovipositing marks of the plum cur- 

 culio, all of which eggs had failed to hatch. 



The season of 1883. when the great mass of plums came into 

 bearing on my place, I think this insect was as plentiful as it was 

 possible for it to be anywhere, (For I had a great amount of late 

 cherries in which they seem to hatch and mature freely). That 

 season I failed to notice a single plum that did not show the well 

 know star and crescent mark of this insect, and as high as twenty- 

 three of her marks on one fruit. Yet the trees matured a full crop 

 of fruit, that sold freely in the market; there were no worms in 

 them. I had four full crops of plums in succession, ending this 

 past season with about one-thirtieth of a full crop — all of these 

 crops showing a continual decrease of the Plum Curculio, ending 

 with the past season, when I calculate that I only had two per cent, 

 of the original number left on the place, or a decrease of ninety- 

 eight per cent. 



This leads us up to some of the grandest, most glorious facts in 

 modern horticulture. They are, that we can have the native plums 

 in abundance everywhere; and another is, that if we plant and fruit 

 these plums abundantly everywhere, that, in itself will protect all 

 our other fruits from its ravages. Or, in other words, it will no 

 longer be known as the most injurious insect of our orchards. 

 Why? If I have told the truth I have shown that this insect can 

 breed only to a very limited extent in most of these plums; and as 

 it seems to prefer these plums as its natural food plant, and seeks it 

 above all other trees in early spring to feed thereon, and being there, 

 finds acceptable fruit in plenty in which to lay her eggs, and but 

 few of the eggs so laid hatch, and still fewer of her young that do 

 hatch can feed to maturity on these plums, the result must be that 

 the insect is well nigh exterminated in this mistaken endeavor to 

 reproduce her kind? 



The wild plum was, and is yet, the natural, and nearly the only, 

 most certainly the preferred, food plant and breeding plant of the 

 plum curculio. What is the explanation, then? It is this. A life, 

 when existing in its natural conditions, and is being preyed upon by 

 another life in some vital point liable to cause its extinction, defends 

 itself against the aggressor by continuously, through many genera- 

 tions, gradually strengthening the weak or threatened point. Or, 

 in other words, the continuous survival of the fittest. By this means 

 we know, or, at least, 1 know, that the fruit of the wild plum has 



