Entouioloijical Society. 



5997 





Scolytus. 



Cossus. 



Condition— 1843. 



Condition- 1847. 



Condition— 1849. 



1 



■* 







Slightly. 



Nearly recovered. 



Recovered. 



2 



5' 



}> 



Most severely, dying. 



Dead. 



Dead, removed. 



3 





5» 



Must severely. 



Nearly recovered. 



Recovered. 



4 







J> 



Slightly. 



Recovered. 



Do. 



5 



5) 







Do. 



Do. 



Do. 





JJ 







Do. 



Du. 



Do. 



7 



?> 



»> 



Severely. 



Du. 



Do. 



8 



>> 



>» 



Slightly. 



Du. 



Do. 



9 



U 





Most severely. 



Nearly recovered. 



Do. 



10 







55 



Slightly. 



Recovered. 



Do. 



11 





75 



Very severely. 



Do. 



Do. 



12 







55 



Slightly. 



Do. 



Do. 



13 





55 



Very severely. 



Do. 



Do. 



14 







55 



Slightly. 



Do. 



Do. 



15 





55 



Most severely. 



Nearly recovered. 



Do. 



1() 







55 



Do. 



Do. 



Do. 



17 





55 



Slightly. 



Do. 



Do. 



18 







55 



Most severely 



Do. 



Do. 



" From this tahle the condition of the trees will be seen previous to being sub- 

 mitted to my plan. Now, before we proceed to speak of treatment, there are two very 

 important stages to be settled : first, is the tree diseased before it is attacked by the 

 Scolytus? and, in the second place, does the attack of the Scolytus prove injurious to 

 the tree? 



"As regards the condition of the tree, T think we had in the Garden of the Royal 

 Botanic Society a sufficient number of sickly ones to enable us to come to a very fair 

 conclusion. The number first planted was 242; in 1843, 67 had a healthy appear- 

 ance; 66 were attacked by the Scolytus, 10 by the larvae of Cossus Ligniperda ; 

 99 had sickened or died, and had been cut down, 62 of which sprouted again, and 37 

 quite perished. With respect to the condition of the healthy ones, the en)bankment 

 equally adjoined them in places; but of the 18 that were allotted to me no embank- 

 ment existed ; therefore this could not have been the cause of Nos. 2, 3, 7, 9, 11, 13, 

 15, 16 and 18 having such a sickly appearance; and if it arose from their roots pene- 

 trating a gravelly soil, the mere fact of partially barking could by no possibility restore 

 ihem to health and vigour. I think we may fairly say that this is a self-evident pro- 

 position. And, again, what is the appearance of a tree languishing from defective 

 soil ? We see it first in the leaf, which is small and unhealthy in colour ; the termi- 

 nal branches next gradually decay, piece after piece breaking away, until the longer 

 branches present what is generally called a 'stag-horned appearance,' and the tree 

 finally perishes ; but this is not brought about in a day or a week, being usually the 

 affair of some few years, for as long as nutriment can be obtained the crippled tree 

 exists in its withering and fading condition. But when we find a tree dead, with ter- 

 minal branches profuse and perfect, we certainly, under ordinary circumstances, 

 should not say that tree had died from defective nutrition in the soil, but that, from 



* The presence of either Scolytus destructor or Cossus larvae is indicated by „ 

 according to the heading of the column in which they aj)pear. 



