294 Seifriz . — Observations on some Physical Properties of 
immiscibility of the protoplasm. Perhaps it is only the true sol state 
of protoplasm (the endoplasm of Amoeba , e. g.) which is sometimes water- 
miscible, and only when the liquid endoplasm rapidly attains a higher 
viscosity at its exposed surface does it save itself from destruction. This 
hypothesis would demand a gel state of protoplasm even when the living 
substance is of quite low viscosity. Whatever our point of view we have 
the experimental fact that living, normal protoplasm does not mix with 
water, unless extremely dilute, and even then it does so in only half the 
cases observed. 1 
The affirmation of the miscibility of protoplasm in water robs, it seems 
to me, the living substance of all organization, robs it of its innate power to 
maintain its individuality, and makes of this highly complex colloid a com- 
paratively simple aqueous dispersion which can be mixed in water with no 
change other than a dilution. In view, then, of these facts, how are we to 
interpret the taking up of water by protoplasm ? 
The taking up of water by protoplasm is, in my opinion, essentially an 
imbibition process. The colloidal constitution of protoplasm is responsible 
for the absorption and retention of water by the living substance. 
Summary. 
1. Protoplasm when subjected to dissection in water is, in by far the 
greater number of instances, immiscible in the surrounding medium. 
2. When the condition of water-miscibility of protoplasm does occur, 
it is ascribable to one of two factors — extreme liquidity or disorganization 
(i. e. death). 
3. The immiscibility of protoplasm is possibly due to the characteristic 
colloidal nature of the living substance, which may be merely colloidal 
structure, although chemical constitution is probably also a controlling 
factor. 
4. The absorption and retention of water by protoplasm is essentially 
an imbibition process. 
Bibliography. 
1 Arthur, J. C. : Movement of Protoplasm in Coenocytic Hyphae. Ann. Bot., vol. xi, pp. 
49 i - 5°7, 1897. 
2. Barber, M. A. : The Pipette Method in the Isolation of Single Micro-organisms and in the 
Inoculation of Substances into Living Cells. Philippine Jour. Sci., Sec. B., vol. ix, pp. 
307-60, 1914. 
3. Bary, PI. A. de : Die Mycetozoen. Leipzig, 1864. 
1 In connexion with the problem of protoplasmic miscibility it is interesting to consider the 
protrusion of ‘naked’ protoplasm through clefts and pores in diatoms. It is difficult to conceive of 
such an external stream of protoplasm, by means of which diatoms are supposed to move (33, p. 118), 
as water-miscible. 
