4 Mr Gray, The Effect of Hypertonic Solutions 
the simple statement that the chromosomes of L. acutus are more 
susceptible to changed environment than those of EH. esculentus. 
In order to explain these facts I would put forward the following 
suggestion in the most tentative way. It is based on the view 
that the relation of a cell to electrolytes in its surrounding media 
is of prime importance to the existence of that cell. The work of 
McClendon and R. S. Lillie has shewn that after fertilisation the 
surface membrane of the egg is more permeable to ions than 
before. It has also been demonstrated that the CO, production of a 
dividing cell changes just before each division, 2.., there is a slight 
increase in permeability*. It is also highly probable that the 
effect of hypertonic solution upon a cell is to decrease its permea- 
bility to ions. (Sutherland; Lillie.) . 
The whole of the evidence in favour of the view that the 
permeability changes of the egg membranes (plasmic and nuclear) 
are of profound importance to the activities of the cell cannot be 
discussed in full, but the following extract from a recent paper by 
R.S. Lillie has a peculiar interest in connection with the phenomena 
discussed in this paper. 
“The conclusion that many pathological conditions have their 
primary origin in abnormalities of the limiting membranes of cells 
is an obvious corollary of any view that regards such membranes— 
which are essentially insulating surface films of varying ionic 
permeability and electrical polarization—as largely controlling the 
rate and character of the cell processes. If stimulation depends 
primarily upon altered polarization of the plasma-membrane 
due to increased ionic permeability, it is clear that a normal 
response, in the case of any cell, implies a definite condition of 
the membrane. If this condition is permanently altered, the 
cell processes inevitably undergo derangement, and pathological 
changes follow. Such a deranged condition, if not too far ad- 
vanced, may be rectified by restoring the membrane to its normal 
condition....The alteration caused by a toxic agent may consist 
primarily either in increasing or in decreasing the permeability 
normal to the membrane, or in altering in either direction the 
readiness with which the latter undergoes change....The plasma 
membrane cannot undergo marked and prolonged increase of 
permeability without alteration in the nature and proportion of 
the cell-constituents; this involves altered chemical organization 
and eventual derangement of the cell-processes.” 
It is, therefore, a possibility at least that the hypertonic 
solutions exert a toxic action upon the nucleus of a fertilised 
egg by upsetting the normal relationship of the cytoplasm to 
electrolytic ions. 
* The susceptibility of a dividing cell to poisons has also been shewn to be 
rhythmical in the same way. 
