elxvi Journal of the Asiatic Society of Bengal. [N.S., XIV, 
prey not to one but to several organisms. The first falling 
away from health and step towards disease is, therefore, au 
extremely important point and it is just this which requites 
eareful study and which is frequently overlooked owing to the 
absence of obvious external signs such as the death of leaves ot 
twigs. A plant suffering from a deficient water-supply and a 
clogging of its tissues with unutilisable carbohydrates may 
ow no external signs of wilting or withering, also a t 
apparently still healthy with green leaves may have a number 
of its deeper roots more or less completely asphyxiated. Finally, 
it should be remembered that, whereas the direct control of 4 
Occology and sys is, Fapelghenition: no . 
Sylvi orestry this fact has Pe 
epee very eines years and the study of such 5 
factors is the province of the practical sylviculturist who 
base his methods of treatment on such study. In the 
place such questions as the economic management of 
and the detailed study of diseases do not form a pa 
legitimate duties of the sylviculturist. In many oth 
tions, however, the oecologist and sylviculturist d 
_ meet on common ground, and here it is merely a 
mutual agreement and co-operation as to which aspee 
forest in such a wa 
gist, however, should go further and should, if poss 
