45 



away, while the remainder of the bark being relieved from 

 its enemy, forms a healthy callus round the injury, and 

 in course of time completely covers over the shaved part". 

 Though the facts menti oned are the same as those ob- 

 served hère in Suriname, this description of Carruth ers 

 is not quite correct, for the callus is formed first and by 

 its agency the diseased patch is loosened. 



In this way a tree may recover without excision of the 

 diseased tissue, as it was observed in the dry season of 

 1907 in the Saramacca district. The diseased patch was 

 often still présent as a dry pièce of bark, lying loosely 

 on the callus which had formed underneath. I hâve not 

 yet had an opportunity of examining trees in which the 

 disease had penetrated into the wood and which had 

 nevertheless recovered; therefore I am at présent unable 

 to judge as to the way in which this took place. 



Mycological Investigation. 



In the discoloured parts of bark and wood I found the 

 mycélium of a fungus. It sometimes is very scarce, at 

 other times it is found without the least difficulty. It 

 may be especially abundant in the youngest part of the 

 wood. Most investigators hâve also found the mycélium 

 outside of the discoloured patches, I hâve not been able 

 to find it there myself. The mycélium is intracellular and 

 traverses the ducts, the fibres and the woodparenchyma 

 in a longitudinal direction; it sends out many short 

 sidebranches and is often somewhat sinuous; the sinuo- 

 sity in the medullary rays becomes so marked, that it is 

 mostly impossible to trace a definite direction (fig. 5 a 

 and h). By préférence it seems to pass from one cell 

 into another through the pits as has already been obser- 



