132 Proceedings of the Royal Physical Society. 
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and his views I endorse. There exists in each cell an 
intimate relationship not only between the nucleus and its 
protoplasm, but also between all the organs of a cell; and 
as long as this relationship is not broken, and as long as 
the equilibrium between the various organs is not upset, 
so long will the cell be able to live an individual and 
immortal life. . 
Theoretically, a happy state such as that just depicted is 
conceivable; in nature it does not occur. No individual is 
immortal, for the very existence of a cell depends on a 
perpetual change of lower (inorganic) into higher (organic) 
chemical compounds; and if the term individual be given to 
such a chain of progressive metamorphoses occurring within 
the definite organs of a cell, any cause leading to a disruption 
of the normal processes must also lead to a loss of that 
particular individuality. Thus a cell which either undergoes 
division, or which fuses with another cell in the act of 
fecundation, loses its individuality, though the chemical 
constitution of the various plasmata occurring in the cell is 
preserved, and thus the perpetuation of the species ensured. 
Let me repeat, that a cell will not divide or fuse with 
another cell as long as the equilibrium between its various 
organs can be preserved, 7@¢., as long as its individuality is 
not threatened. 
After this short sketch of cellular physiology, let us con- 
sider how parental traits are propagated. 
In a unicellular organism, as represented by Verworn’s 
figure, we have to deal with an individual relying on its 
own resources, and living an existence which is independent 
of other representatives of its own species. Itis not difficult 
to understand how such an organism is able to propagate its 
specific characters either by budding, as in the yeast, or by 
ordinary division (amitotic and mitotic), as in the case of 
Amcebe and white blood-corpuscles, provided that during 
budding or cell division all those organs are handed on 
which are necessary for the maintenance of the individual 
in question; and we know for. certain that during budding 
and division the various cell organs are indeed handed 
on. An artificial division of such unicellular organisms is 
