478 [Assembly 



plantations, In a short period of time, is due almost entirely to the 

 propagation of the larvffi of the Scolytus, which have so greatly in- 

 creased within the last twelve or fifteen years, that it would be diflS- 

 cult to find to-day wnthin the circuit of Paris, or even in the entire 

 department of the Seine, a single tree which has not been attacked. 

 The larvae of the Cossus deeply wound the ligneous parts of the tree, 

 without too much endangering its life. 



The simple taking off in parallel strips, longitudinally, the old 

 bark, down to the young bark, (where the seat of the evil is) (you 

 must not go down to the Liber,) from all the large branches as well 

 as the trunks of the Elms, Apples, Ashes, &c., making from two to 

 six strips according to the size of the trunk or branch, is sufficient to 

 completely purge the tree of the larvffi which infest it and will re- 

 generate, not only the infested , bark of these branches, but all the 

 bark. Experience has proved to me that trees, especially Elms, en- 

 tirely deprived of their old bark, can sustain the greatest cold and 

 drought without any unguent — that of Saint Fiacre or any other 

 whatever. This is an economical and certain method; the old bark 

 is worth, something for fuel or may be used mixed with oak bark for 

 tanning. "• 



I make the incisions on the large branches as high up as possible 

 towards the sources of the descending sap. This decortication or 

 taking off the old barks, perfectly destroys the larvse of insects, and 

 also remarkably augment the production of wood in the stationary 

 trees that are stunted, (rabougris,) such as elms and oaks. Now, 

 admitting that in Paris the l6ngest elms of seventy and eighty years of 

 age and the middle sized ones of thirty or forty years old, produce 

 annually, the first a woody circle of from one to two millimetres 

 thick, and the latter from two to five, the trunks of such trees strip- 

 ped entirely of their old bark, formed the first woody circles of 

 from four to five millimetres thick, and the latter from six to eight 

 millimetres. This remarkable increase I observed to continue in the 

 same proportions the followihg years. This process will restore fe- 

 cundity to old fruit trees. 



This operation is not new, but it has fortunately been much ex- 

 tended. Knight says that apple-trees which he had partially barked, 

 not injuring the tender inner bark or wood, had gained a diameter in 

 two years more than in twenty years before. 



