248 Papers from the Department of Marine Biology. 



change the irritability is not explained by the theory, nor does it take 

 into account other anesthetics which are not lipoid soluble e. g., 

 neutral salts. No distinction is made between the action of anesthetics 

 in the membrane and in the cell interior. Traube (1913 and 1915) 

 considers anesthesia as due to adsorption of the narcotic by surfaces 

 in the cell, especially colloidal particles, due to the lowering of the sur- 

 face tension of water. This causes a decrease in catalytic activity of 

 the surface layer, leading to a decrease in the chemical activity of the 

 cell, especially of oxidations. It has been shown that many substances 

 with the same surface tension have the same physiological action, 

 although this is not always true. The fact that dried micro-organisms 

 free of lipoids can be anesthetized supports this theory rather than the 

 lipoid theory (Warburg and Wiesel, 1912) . On the other hand, the effect 

 of temperature on anesthesia corresponds more closely with the effect 

 on lipoid solubility than on adsorption of the anesthetic (Meyer, 1901). 



That the narcotic acts by interfering with oxidation is held by others 

 besides Traube. Verworn (1913) considers narcosis as an asphyxia- 

 tion, since narcotized cells behave similarly to those deprived of oxygen. 

 Mathews (1914) explains the relation of oxidation and anesthesia by 

 assuming that protoplasm contains an unstable compound with oxygen, 

 which breaks down on stimulation, and the anesthetic forms a stable 

 compound with oxygen and thus prevents its liberation on stimulation. 

 According to Mansfeld (1909), the anesthetic prevents the oxygen from 

 entering the cell by decreasing the permeability of the surface for 

 oxygen. In favor of these theories is the fact that oxygen consump- 

 tion by certain cells and in certain oxidations has been shown to be 

 decreased by anesthetics (Warburg, 1911). However, in these cases 

 the concentration necessary to decrease oxidations is much greater 

 than that necessary to produce anesthesia. Moreover, the experi- 

 ments of Loeb and Wasteneys (1913) on sea-urchin eggs have shown 

 that an anesthetic in the concentration sufficient to prevent cleavage 

 had very little effect on oxidations. A slight decrease in temperature 

 has a much greater effect on the rate of oxidations than an anesthetic 

 of effective strength. 



The membrane theory of Lillie (1909-1916) and Hober (1907) is also 

 important. According to this the anesthetic affects the interior of the 

 cell indirectly, the primary effect being upon the permeability of the cell 

 membrane. The change in permeability is supposed to be connected 

 with a change in the aggregation of colloidal particles, protein and lipoid. 

 Lillie's experiments on Arenicola larvae show that the narcotic prevents 

 an increase in permeability, or in some cases causes an actual decrease. 

 Osterhout (1913) has shown also, in Laminaria, that anesthetics cause 

 a decrease in permeability, as indicated by an increase in resistance to 

 the electric current. This theory takes into consideration the non- 

 lipoid-soluble as well as the lipoid-so ruble anesthetics. 



