BLIGHT. CANKER. INSECTS. 15 



of the respective soils in producing an early in- 

 stead of a late growth. Whenever blight has 

 occurred (he continues), I know of no remedy 

 but free and early cutting. In some cases it will 

 remove all diseased matter ; in some it will ale- 

 viate only ; but in bad blight, there is neither in 

 this, nor in any thing else that I am aware of, 

 any remedy. It may be inquired why fall-grow- 

 ing shrubs are not always blighted, since many 

 kinds are invariably caught by the frost in a 

 growing state ? I reply, first, that we are not to 

 say that every tree or shrub suffers from cold in 

 the same manner we assert it of fruit trees, be- 

 cause it has been observed it must be asserted 

 of other trees only when ascertained. I reply 

 more particularly, that a mere frost is not sup- 

 posed to do the injury. The conditions under 

 which blight is supposed to originate are : a grow- 

 ing state of the tree, a sudden freeze, and sudden 

 thawing. We would here add, that many things 

 are yet to be ascertained before this theory can 

 be considered as settled." The editor of the 

 " Horticulturist," on the subject of the frozen-sap 

 blight, says, " It is not confined to the pear tree 

 alone : we have seen it in several other trees, the 

 Ailanthus, Catalpa, and the Spanish Chesnut. 

 The latter tree, especially, shows very frequently, 

 while standing in the nurseries and still growing, 

 the same symptoms as the blighted pear tree ; 

 first, early in the spring, patches of shrivelled 

 and discolored bark near the lower part of the 

 trunk ; second, about the beginning of summer, 

 sudden withering of the foliage, death of the 

 branches, and often of the whole tree. A most 

 important question which we now reach is this : 



