PROTOPLASMIC PERMEABILITY 149 



iiles of lecithin suspensions when ether or chloroform is added, 

 the anesthetic being taken up by the suspension and presumably 

 by the lecithin globules. Lillie^* has suggested that anesthesia 

 may be caused by a swelling of the lipoid particles due to the 

 absorption of the anesthetic by them. In the case of the organic 

 anesthetics such as ether and chloroform this explanation might 

 be adequate though it is doubtful if the amount of anesthetic 

 necessary to produce physiological effect is sufficient to cause 

 any large degree of swelling of the particles by simple addition 

 of volumes. The explanation is inadequate to account for the 

 anesthetic effect of magnesium salts^'' and it seems more probable 

 that if swelling of the particles (or globules) occurs in anesthesia 

 it is secondary and due to an absorption of water caused by the 

 anesthetic rather than to the added volume of the anesthetic 

 itself. 



It is interesting that the hypothesis presented in this paper 

 receives support from a series of facts which are not closely 

 related to permeability. It has long been known that the ''con- 

 sistence" or viscosity of protoplasm is variable. Some piroto- 

 plasm is practically liquid; some has the consistence of a stiff 

 jelly. Recently two independent lines of investigation have 

 shown that changes from liquid to semi-solid condition and vice 

 versa may occur in living protoplasm spontaneously or under 

 chemical or mechanical stimuli, and that these changes may be 

 reversible. These investigations are the ultramicroscopic stud- 

 ies of Gaidukov,^^ Price- and others and the experiments of Bar- 

 ber,23 Kite^^ and Chambers" on micro-dissection of the cell. 

 Such changes of consistence are easily explainable as due to 

 changes in the distribution of water between the phases. Similar 



1" Amer. Jour. Physiol. 29: 395 (1912). 



20 Meltzer and Auer, Amer. Jour. Physiol. 14: 361-388 (1905); Zentbl. Physiol. 

 27: 632-635 (1913). 



21 Ber. deut. bot. Ges. 24: 107-112, 155-157, 192-194, 581-590 (1906); Dunkel- 

 feldbeleuchtung und Ultramikroskopie in der Biologie und der Medizin, 1910. 



22 Science Progress 8: 343-354 (1913); Annals of Botany 28: 601-532 (1914). 



23 Jour, infect, diseases 8: 348-360; 9: 117-129 (1911). 



2" Biol. Bull. 25: 1-7 (1913); Amer. Jour. Physiol. 32: 146-164 (1913); Kite and 

 Chambers, Science 36: 639-641 (1912). 

 "Science 40: 824-827 (1914). 



