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been subjected to the twisting power along with the other 
parts of the cell, and thus its spiral appearance is pro- 
duced. 
What becomes of the primordial utricle, I cannot state 
with certainty. After the disappearance of the cellulose 
there is an envelope left, which surrounds the contents of 
the cavity, this may be the primordial utricle, or the film 
left by the drying up of the protoplasmic or organising 
fluid. 
If the solvent is made to come into contact with the ends 
of recently-cut cotton a beautiful trumpet mouth is pro- 
duced — the exposed surface of cellulose has expanded and 
pushed back the external covering into folds — the contents of 
the cell may, in this case, be seen projecting from the mouth 
of the trumpet form. 
Long after the complete dissolution of the cellulose has 
taken place, the external membrane remains just as the 
rotation or twistings had left it, some portions in the form of 
rings, which had been the ligatures between the bulbous 
expansions, other portions as irregular spirals. 
The cell contents also remain as twisted corrugations. 
From the observed difference in solubility between the cellu- 
lose and the external and internal matter, I should imagine 
a difference in constitution. 
A few experiments have led me to suspect that some of the 
spiral appearances observed in hemp and flax fibres during 
dissolution may possibly be caused by the mechanical action 
of the solvent employed. 
P.S. — In making the cupric oxide with ammonia, the 
oxide of copper requires a thorough washing before dissolving 
in the ammonia. The presence of any salt of ammonia, even 
in very small quantities, interferes with its power in dissolving 
cotton. 
