16 
PHYSIOLOGY: E. B. HARVEY 
twitching of a muscle in pure NaCl; the only responses given were the 
momentary bright flashing and the steady glow. The latter response 
was called forth by anesthetics, cold (5°-0°C.), heat (43°-49°C.), acids 
and alkalies, fresh water, and a constant galvanic or interrupted in- 
duced electrical current. Cells injured by puncturing with a needle 
or by passage of an induced current respond to mechanical or electrical 
stimulation by a flash just as normal cells do. If, however, the cells 
are completely broken to fragments by pressing them through cheese- 
cloth, they do not flash on stimulation although they do give a steady 
glow. Light production does not occur in absence of oxygen. The 
supposition that the cells are ordinarily impermeable to oxygen but 
become permeable on stimulation and on death, is not true, however, 
for the cells deprived of oxygen immediately give light when oxygen is 
readmitted, without being stimulated mechanically or in any other way. 
Noctilucas may be anesthetized by certain concentrations of ether, 
chloroform, thymol, chloretone, ethyl and butyl alcohol so that they 
fail to give a flash on stimulation, but they always give a very faint 
glow; this disappears and the normal response returns on removing the 
anesthetic. Noctilucas differ in this respect from luminous bacteria 
whose light giving power can be completely anesthetized. (E. N. Har- 
vey, Biol. Bull., 29, 1915, p. 308). Although the anesthesia of many 
processes, e.g., the contraction of heart muscle, cell division and growth 
has been shown to be independent of the consumption of oxygen, we 
should expect the anaesthesia of light production to be dependent on 
the consumption of oxygen since this process is a luminescent oxidation 
which will take place in solution^ in a test tube free from cells. That 
this oxidation is different from that in most cells is shown by the fact 
that KCN has no effect on the light production in Noctiluca in relatively 
high ccncentrations, whereas it quickly paralyses the oxidations of 
most cells. The question arises whether the anesthesia of luminous 
cells is due to the fact that oxygen cannot pass through the membrane, 
or to the fact that it cannot be used. The latter alternative is suggested 
by the experiment of removing oxygen from the cells and readmitting 
it, thus showing that oxygen can pass the membrane at any time. The 
question is answered by an experiment in which the cell substance of 
anesthetized cells was permitted to come in contact with dissolved 
oxygen. Narcotized cells were broken up by shaking with sand, and 
it was found that they produced only a faint light whereas normal cells 
so treated became very brilliant. The anesthetic must therefore at- 
tack the mechanism of the utilization of oxygen in the cell, and not the 
permeability of the cell membrane for oxygen. 
