THE STRUGGLE FOR LIFE. 209 
there is a cellular life, quite independent of the general life 
of the whole body. Once however the somatic life is 
destroyed, the lives of the separate cells soon come to an 
end, and this also occurs, even when they are merely sep- 
arated from the living body without the destruction of the 
life of the whole animal. On the other hand, the destruc- 
tion of a certain proportion of the constituent cells, at once 
puts an end to the collective life of the whole. 
We here come, as we so constantly do when examining 
these problems, to the insoluble mystery of Life. In one 
sense the life of the individual is the sum of the lives of 
his constituent cells, yet, take away millions of these cells, 
as is done when a limb is amputated, the wound once 
healed, life goes on as before. When the collective life is 
destroyed, at once the force which held the complex organic 
compound of protoplasm together is lost, and what is called 
decay begins, and the Scavenger Bacteria commence their 
work, and the body is reduced to simpler constituents, 
which can then again and again, in myriads of ways, be 
used in the laboratory of Nature, for the construction of 
new bodies, and so continue their function in the never- 
ending cycle of life. 
Nor is this all. No animal is the same for any appre- 
ciable period of time: the so-called man of to-day, is not 
the man of yesterday, after the lapse of a few years, very 
little of the material body of the individual remains un- 
changed: whatever identity there be, is in the mind, and 
who shall say that this remains the same from day to day? 
Not I, for one, since the impressions left on the brain by 
earlier events become obliterated, and the halls of memory 
filled with new guests. But for all this the general 
appearance of the individual remains unchanged. 
Thus the life of the body, is in a way the lives of its 
constituent cells, and the material of which they are formed 
is in a state of continual change. Further than this, these 
