1883.] The Variability of Protoplasm. 927 
reasons for doubting that protoplasm, as we know it, is the only 
possible physical basis of life. We are beginning to recognize 
that the essential quality in protoplasm is its high atomed chem- 
ical composition and its molecular instability, not some occult 
property which can exist only in this special compound of 
-O.H.N. In fact there is satisfactory reason to believe that in 
terrestrial protoplasm there frequently occur differences in com- 
position, which differences may, for all we know to the contrary, 
be occasionally considerable. If it varies thus here, it may vary 
far more elsewhere, and under conditions of temperature and sur- 
face relations different from those of the earth, it seems not im- 
possible that a basic organic substance may exist widely different 
in its chemical composition from that with which we are ac- 
quainted. 
This question has been considered, from the chemical point of 
view, by several writers. The first definite declaration which we 
find on the subject, is that by Professor E. D. Cope, in a lecture 
before the Franklin Institute, February, 1874,’ in which he sums 
up his conclusions as follows: “ We are not necessarily bound to 
the hypothesis that protoplasm is the only substance capable of 
Supporting consciousness, but to the opposite view, that the prob- 
abilities are in favor of other and unspecialized, but unknown 
forms of matter possessing this capacity.” The same view was 
expressed in more detail in his paper entitled, “ On Arches- 
thetism.”? 
Dr. Persifor Frazer has considered at some length the constitu- 
tion of protoplasm in his paper entitled, “ A Speculation on Pro- 
toplasm.”* He concludes that “If the sarcode or protoplasm be 
Susceptible of slight chemical changes, and in fact suffers such 
changes without losing the power to fulfill its function of repair- 
ing waste tissue, then in the progress of the decay of worlds, and 
the changes of external conditions consequent upon it, Darwin's 
law of survival must inevitably be felt where an accidental altera- 
tion of the substance of the sarcode and the resulting changes 
impressed upon the structure, enable one animal to live where 
others perished.” He deems it possible that chemical diversities 
in protoplasm may become so great as to permit the existence of 
"Consciousness in Evolution, Penn Monthly, Aug., 1875. 
* AMER. NATURALIST, June, 1882. 
* Amer. NATURALIST, July, 1879. 
