I have been watching all whiter for the results of this insect, or for its modes of action 

 and transformation; But with the most careful search could discover nothing, and had in 

 fact, almost given up in despair, when one day, by accident, I found it lay horribly appa- 

 rent, right before my eyes — and that I had seen it a thousand times before without know- 

 ing it. I will, therefore, prescribe a third experiment in the process. 



3. Approach that young pear tree, so healthy, thrifty, and clean — not a blemish can be 

 found on it. Its growth, though excessive (it may be,) appears perfectly sound and good 

 — and even the last cold winter, of 20 degrees below zero, has evidently had no power to 

 injure in the least its glossy trunk, its bark, or even its terminal buds. All is in the 

 brightness of a joyous and storm-defying youth. You, of course, observe little white 

 specks on all parts of the bright brown wood — for such is its nature. But observe again; 

 some of those little whitish specks are larger than the rest, and have the appearance of a 

 mite of mould on the surface of the bark. Well, what strange thing is a mite of mould 

 on a large tree.'' But there are more, and more, and more, and the longer you look, the 

 more jou find. Take now the point of your knife, and press one of these little insignifi- 

 cant patches of mould, and listen closely — you hear a crash under the knife. Ha! j'^ou 

 have crushed a little world. You can, even with the naked eye, see its brown blood flow 

 beneath the relentless steel, and though it be a world of pear tree fiends, hostile to them 

 and to you, you will find little cause to exult, when you see how many more such worlds 

 remain unconquered around you. Now take one of these little specks and peel it up from 

 the bark, and appl}"^ your microscope, and j'ou will find your speck of mould a most deli- 

 cate and finely wrought texture of silk, spread as an impervious awning over a great mul- 

 titude of little reddish brown eggs, of oblong form, and of beautifully smooth regular 

 shape and texture, still so small that scores of them are safely packed under this speck, 

 this particle of a silken coccoon; and even on white paper — to the naked ej'^e are scarcely 

 visible as dust — though most beautifully apparent through the microscope. 



4. But once more return to your tree; examine with a sharp knife and a microscope, and 

 you will find on the pear, wherever the eggs are .sound, and nearly ready to hatch, the 

 bark, sometimes for one-fourth of an inch round the nidus, is already, (April 1, 1852,) 

 turned a reddish brown, in some cases quite down to the wood, and with every accession 

 of spring warmth, it is constantly extending. These eggs, themselves, seem to be a dead- 

 ly virus to the bark and sap, especiall}- of the pear tree; and in many cases there is a hole 

 eaten down from the eggs directlj' into the bark, quite to the wood of the tree, bearing all 

 around it, the evidences of poisonous influence. Whether the parent insect emerged from 

 these holes in the bark, or retreated into the tree through them after depositing its eggs, or 

 simply scarified it for the benefit of its future progeny, cannot be told without future re- 

 search. Where the branch is not killed, as usually happens on the apple, these holes re- 

 main, after all other appearances are gone, still visible to the naked eye. All these mani- 

 festations are more usually found near a bud or branch, a short crotch in a limb, or at the 

 points where the bark is changing from smooth to rough, as if partial to places where 

 there is some interruption of flow, or fulness of sap; though frequently on all parts of a 

 peculiarly vigorous growing shoot or limb, where, indeed, the conditions would be much 

 the same. 



Now that this is thi cause, not the consequence, of the blight which appeared here last 

 season, any man that has these e3'es may see; and numbers of intelligent men have ex- 

 amined my trees, (of which I have several hundred,) with me, and all concur with me in 

 inion. But this blight bears no more analogy to the blight which I described 

 ago as the " sun-blight," than the worms which ate King Herod's bowels bea 



