[Vor. 5 
254 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
that it is untenable. Thus, Loeb and Wasteneys (713, 713%) 
have reported that chloroform, among other narcotics, pro- 
duced complete narcosis in fertilized eggs of the sea-urchin, 
without practically lowering the rate of oxidation; similar 
results were obtained with fish embryos and with medusae. 
Modern theories of narcosis, based on studies of membrane 
permeability, structure, and composition, have been ex- 
pounded since the well-known work of Overton (795). "This 
investigator published data on the osmotic properties of plant 
and animal cells, in which he adduced evidence to show that 
although the permeability of solutions towards protoplasm 
decreased with their specific gravity, the size of the molecule 
was not the sole conditioning factor. This work was the fore- 
runner of his study of narcotics (’01) in which he reached 
conclusions previously arrived at independently by Meyer 
(’99) and which form the basis for the much-disputed Meyer- 
Overton theory of narcosis. According thereto the conclu- 
sions are: 
1. All chemically ‘‘indifferent’’ compounds which are lipoid 
solvents act as narcotics on protoplasm wherever they come 
into intimate contact therewith. 
2. Action is effected first and most strongly in cells in whose 
chemical composition lipoids predominate,—hence especially 
in nerve cells. 
3. The relative effectiveness of such narcotics is dependent 
upon their mechanical affinity for lipoids, on the one hand, 
and for the other cell constituents, especially water, on the 
other. It is determined in a mixture of water-soluble and 
lipoid constituents upon the partition coefficient; i. e., the 
effect varies directly with increase in lipoid solubility. 
Lepeschkin (711) essayed to throw light on the chemical 
nature of the plasma membrane and of the dispersion medium 
of the outer protoplasmic layers, wherein he considered 
osmotic selective power to reside. This he attempted by a 
comparison of permeability changes. Comparisons were 
made of the concentrations of various solutions sufficient for 
albumin coagulation with those necessary for the complete 
coagulation of membranes of Tradescantia, Spirogyra, and 
