22 WORCESTER COUNTY HORTICULTURAL SOCIETY. [1885. 



Station, — differs from the common experience in this section of 

 the country in that it asserts : 



" All varieties of the Pear in the orchard were attacked, but the 

 Bartlett seemed more susceptible to a rapid progress of the disease 

 than any other." 



Hereabouts, — in the City of Worcester and vicinity, the Belle 

 Lucrative and Glout Morgeau suffered worst ; until of late years, 

 when Clapp's Favorite has surpassed them in this evil respect 

 and rapidly attained to a sad preeminence. The Bartlett, while 

 not exempt from attack, has remained comparatively unharmed ; 

 still bearing, as when first introduced, its excessive crop of what 

 might well be termed the Universal Pear ! In the garden of 

 the present writer, the Bosc, Seckel, and "Winter Nelis, were 

 never injured, scarce assailed even ; nor the Comice, until the 

 past summer when some twigs were partially affected. Yet 

 those trees grew among Raspberries which exact heavy fertiliza- 

 tion. It is due to the well-earned reputation of that Experiment 

 Station, to quote its own language: 



" Last year the infectious nature of the disease was established by a 

 lai'ge number of artificial inoculations, made under circumstances 

 which admitted of no doubt of the result. This year the disease has 

 shown itselt over one-third of the orchard and attacked trees in the 

 adjoining grounds, nursery stock and hawthorn hedges. 



The observations and experiments have proved that the disease 

 enters the branches through the tender shoots at the ends or through 

 the flowers, thereafter progressing steadily downward toward the 

 trunk. In one instance it entered the trunk through a young shoot 

 and destroyed the entire tree. All varieties of the pear in the orchard 

 were attacked, but the Bartlett seemed more susceptible to a rapid 

 progress of the disease than any other. In addition to the out-door 

 observations a series of in-door experiments proved that the germs will 

 live and grow in a sterilized infusion of corn meal, hay, barnyard 

 manure, green fruit and starch. The important jjoint established is 

 that they will thrive outside the tree in dead organic substances. The 

 final conclusions reached are: — 



The disease is due to living germs. These germs can live and 

 multiply indefinitely in any damp spot where there is decomposing 

 vegetable matter. From such places they are raised into the air when 

 dry, or carried up by moisture. From the air they lodge upon the 

 trees, and when the conditions are favorable, pass into the tissues and 

 cause the blight. The conditions referred to are in general (1) very 

 tender tissues, such as are found within the flowers and at the ends of 

 expanding shoots in spring, and (2) a moist atmosphere. No varieties 



