126 PLANT LIFE ON THE FARM. 
possible in the case of an analogous injury done to one 
of the higher animals. The lower the organism, the less 
special in its conformation and construction, the more 
independent are its constituent cells. The higher the 
organism, and the more specialized its structure, the 
more dependent one upon another are the structural ele- 
ments of which it is compounded. 
Natural death may be described as an exhaustion of 
the protoplasm—its water evaporates or is drafted else- 
where ; and so with its soluble or liquid contents—the 
insoluble and the useless remain behind. We see this in 
the case of the leaves every autumn ; their protoplasm 
dries up, their chlorophyll degenerates and disappears ; 
they are emptied of starch and other matters, which are 
conveyed to some other part of the tree to be stored up 
for future use by the new growths in the following sea- 
son, until at length nothing is left but a framework of 
dry cellulose, a quantity of mineral or earthy matter, and 
such material as could not be dissolved or transported. 
In other organs the continuous maturing process at 
length results in the blocking up of the cells and tubes 
by continued deposit in the interior. Osmosis can no 
longer go on between them, for their altered structure 
prevents it, and in consequence the protoplasm disap- 
pears. Just es in human beings, the minute blood-ves- 
sels get ‘“‘ bony” or otherwise deteriorated in structure, 
so do the cells and fibres of plants become unfit to carry 
on the processes of life. 
For the purposes of the cultivator, it is very desirable 
that he give an eye to the way in which plants die and to 
the causes in which induce death. The subject may be 
looked at from various points of view. From the struc- 
tural point of view, death may begin in the cells of the 
root, in those of the stem, in those of the intermediate 
*‘ collar,” or in those of the leaves, and the appearances 
presented will be found to differ correspondingly. 
