STATE HORTICULTURAL SOCIETY. 47 



tive man coughs, or an itching man scratches only because he has become transferred 

 into a barking and scratching menagerie, why may not trees and vines follow a similar 

 law, and exhibit a .similar phenomenon? 



If so, then I contend that the first step toward tbe mastery of these diseases, is to 

 clearly point out the nidus of their spores ; where they germinate and hold over from 

 year to year; and to learn what will kill oil' these spores in their nidus. Sulphur, the 

 sulphates and sulphites, if they could be got into the dead streaks, or into the sap of the 

 tree ; spirits of Turpentine and lamp black, the alkalies or soap, salt or iron-rust, if they 

 could be made to reach these spores without killing the wood of the tree, would proba- 

 bly prove effectual. Hence, the vulgar idea of hanging old iron or throwing black- 

 smith's cinders about pear trees, like many other sayings in the mouths of people without 

 theories, may be far more philosophical after all, than the pedants that laugh at it. In 

 cases of trees sound and healthy within, such applications by the trickling down of these 

 oxides in the rain, may kill off the spores on all the dead patches of wet bark without ; 

 while, if the tree was hollow, or rotten, or defective within they would do no good ; 

 hence, they are sometimes reported as useful and then again as utterly failing ; both of 

 which are likely to be the fact. 



Useful only when the nidus is on the outside of the tree, but wholly useless if there 

 is rotten wood within, forming a nidus wholly out of their reach. But if these sugges- 

 tions are correct, the main practical inference is one of prevention rather than of "ure, 

 and maybe summarily stated thus: avoid moist dead wood or stagnated bl 

 SAP in your vineyards or pear-orchards ; whether in top or root, within or without, as 

 you would avoid a plague spot; and of course avoid all causes whatever, that can 

 produce such a nidus for Cryptogams, or their incipient spores; cover tender vines 

 without failure ; allow no frozen sap, or sap dead and poisonous from any cause, to 

 become absorbed into the tree or to descend toward the roots, to poison and kill fila- 

 ments of wood there for a future nidus of these spores ; over every wound made in 

 pruning, put on wax or white lead, or coal-tar, or something to make sure as possible 

 that no future nidus for Cryptogams shall be made there, either outside or inside of 

 the tree. Years ago I was convinced that the greatest of all enemies to fruit trees in 

 the West was the saw and axe ami jackknit'e of the barbarian cultivator; eternally in- 

 flicting wounds he had neither the sense to dress or the skill to cure. I so expressed 

 myself in those earlier papers, though I did not then so clearly see the full results of 

 this mischief. I am fully aware that the further question must arise, namely : How do 

 we know that these fungi are not the mere scavengers of disease, feeding only on parts 

 or particles already dead, and not at all on any really living tissue? so that they would 

 then become only a consequence of disease, produced by some anterior cause, and not 

 the cause itself. I answer I do not know ; I do not think it is as yet proved that any 

 of these vegetable spores first begin their germination on any living tissues whatever. 

 But the reports of Dr. Salisbury and others seem to my mind to prove, that while in 

 all cases they may and probably do first attach themselves to particles of dead matter, 

 as the only nidus in which they can first begin to germinate, still as their growth pro- 

 gresses and extends, they do seem to have the power of in some way, poisoning and 

 killing and thus absorbing the cells of contiguous living structures of the more tender 

 parts, like soft shoots, soft bark and fruits, though not perhaps of the solid fibre of 

 the wood itself. Hence their destruction is first manifested only in these softer parts. 

 For as iu their upward growth or ascent from their original uidus toward the top of 



