Protoplasm by Aid of Microdissection . 289 
a process of diffusion or one of imbibition. Consequently, if we define 
miscibility as capability of diffusion, a solution of the problem of the 
miscibility of protoplasm in water resolves itself into the problem just 
stated, namely, Is the taking up of water by protoplasm a phenomenon of 
diffusion or one of imbibition ? Should we decide that it is an imbibition 
process, are we then justified in looking upon protoplasm as water-miscible? 
The former question is not readily nor irrefutably answerable. As for the 
latter, I think that we are quite justified in saying that miscibility and 
imbibition are not, in certain important respects at least, identical. It 
would be carrying our interpretation to the point of absurdity to grant, 
e. g., that a blotter or a sponge is miscible in water. 
The question, Is protoplasm miscible in water ? is, then, best considered 
first in its simplest form, taking a dictionary definition of miscibility. If 
miscibility means capability of mixing, does protoplasm mix with water 
when the two are brought together ? 
To begin with, we know of certain so-called ‘naked’ masses of proto- 
plasm, such as Amoeba and myxomycete plasmodia, which live in water. 
Self-preservation of the organism, therefore, would demand that this proto- 
plasm be immiscible in water. But we are told that these masses possess 
an outer layer which protects the protoplasm. To this one can justly reply 
that the outer layer is itself protoplasm, differing somewhat from the inner 
protoplasm, to be sure, but essentially protoplasm. (If, of course, the 
plasma-membrane is a typical precipitation membrane, and therefore an 
entirely new product, which, however, I do not believe to be the case, then 
the above reply is not valid. Chambers, who supports the view that proto- 
plasm is miscible in water, must, since he makes surface layer synonymous 
with ectoplasm (8, p. 4), admit that this surface is essentially protoplasm. 
What Fischer holds regarding the nature of the outer surface of protoplasm 
I cannot say. He ( 15 , p. 158) does not, however, look upon it as a mem- 
brane. Without further qualification this hypothesis of the absence of 
membranes about cells precludes the miscibility of protoplasm.) But if 
there is some objection to looking upon this outer layer as protoplasm, or 
if it is said that its immiscibility is not proof of the immiscibility of the 
inner protoplasm, we can carry our investigation farther and tear open some 
cells and see what happens when a fresh surface of protoplasm is exposed 
to water. This simple and direct method of deciding such a problem was 
the one employed by the pioneer workers on protoplasm, who were not 
greatly influenced by theories in molecular physics and colloid chemistry. 
The keenly analytical observations of early investigators, because of the 
simple and direct methods employed, are, it seems to me, of more than 
historical interest. 
The first mention of ‘ sarcode the original zoological name for proto- 
plasm, is in Dujardin’s ‘ Recherches sur les Organismes inferieurs ’ (1835). 
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