The Effects of Carbon Dioxide on the Consistency of Protoplasm

A short exposure to carbon dioxide of various cells causes a decrease, and a longer exposure an increase in the viscosity of the protoplasm. 2. Both of these effects are reversible, though the second one tends to pass into an irreversible coagulation if the exposure is sufficiently long continued. 3. The local application of carbon dioxide to Amœba can influence a striking way the formation of pseudopodia. 4. It is suggested that carbon dioxide may be an important factor in producing many of the natural changes in protoplasmic consistency which have hitherto been unexplained.