406 CASUALTIES OF VEGETABLES. CHAP. XII* 



or chinks, by means of the expansion of the frozen 

 sap. But a cleft thus occasioned often degenerates 

 into a chilblain that discharges a blackish and acrid 

 fluid to the great detriment of the plant, par- 

 ticularly if the sore is so situated that rain or snow 

 will readily lodge in it, and become putrid. The 

 same injury may be occasioned by the bite or 

 puncture of insects while the shoot is yet tender ; 

 and as no vegetable ulcer heals up of its own ac- 

 cord, the sooner a remedy is applied to it the better, 

 as it will, if left to itself, ultimately corrode and 

 destroy the whole plant, bark, wood, and pith. The 

 only remedy is the excision of the part affected, and 

 the application of a coat of grafting wax.* 



* 



SUBSECTION VII. 



Dry gan- Gangrene. Of this disorder there are two varie- 

 ties, the dry and the wet. The former is occasioned 

 by means of excessive heat or excessive cold. If by 

 means of cold, it attacks the leaves or young shoots, 

 and causes them to shrink up, converting them from 

 green to black; as also the inner bark, which it 

 blackens in the same manner, so that it is impos- 

 sible to save the plant except by cutting it to the 

 ground. If by means of heat, the effects are nearly 

 similar, as may oftentimes be seen in gardens, or 

 even in forests, where the foresters are allowed to clear 

 away the Moss and withered leaves from the roots.-}- 



* Willdeaow, p. 354. | Ibid. p. 355. 



