W. J. V. OSTERHOUT 177 



All of these papers deal primarily with the effect of anesthetics on 

 respiration. The special interest of this problem is too well known to 

 require extensive discussion. Of late it has centered largely about 

 the theory of Verworn, which states that anesthesia is a kind of 

 asphyxia, due to a checking of respiration by the anesthetic. 



Although this theory has been widely accepted there are excellent 

 reasons for regarding it as invalid. Among these may be mentioned 

 the observations of Warburg, i" who found that phenylurethane in- 

 hibited cell division in the sea urchin egg without altering the con- 

 sumption of oxygen, and those of Winterstein^^ who found that 

 anaerobic animals are easily narcotized, which is difficult to under- 

 stand if narcosis depends on interference with oxygen consumption. 

 Loeb and Wasteneys^^ showed that to produce complete narcosis in 

 Fundulus embryos by lowering the rate of respiration (by means of 

 KCN) it was necessary to diminish respiration to one-fourteenth of 

 the normal; but the same degree of narcosis could be produced by 

 chloroform with a lowering of respiration amounting to only 5 per 

 cent (or even less). In this case it would appear that anesthesia is 

 not due to the checking of respiration by the anesthetic but to some 

 other mode of action. This conclusion was confirmed by a variety 

 of experiments made with other anesthetics and upon other organ- 

 isms. Winterstein^^ in a later paper has shown that in the spinal cord 

 of the frog, anesthetized with alcohol, the rate of respiration is 

 above the normal. 



The experiments upon plants made by various observers^^ are not 

 in agreement. This is doubtless due to differences in the method 

 of experimentation. One point of great importance which has been 

 brought out in recent studies, particularly by those in this series, 



10 Warburg, O., Z. physiol. Chem., 1910, Ixvi, 305. 



11 Winterstein, H., Biochem, Z., 1913, li, 143. 



12 Loeb, J., and Wasteneys, H., /. Biol. Chem., 1913, xiv, 517; Biochem. Z., 

 1913, Ivi, 295. 



1^ Winterstein, Biochem. Z., 1914, Ixi, 81. 



1^ For a review of the literature see Czapek, F., Biochemie der Pflanzen, Jena, 

 2nd edition, 1913, i, 195 ff. See also Ewart, A. J., Ann. BoL, 1898, xii, 415, and 

 Appleman, C. O., Am. J. Bot., 1916, iii, 223. For a general review of the litera- 

 ture on animals, see Winterstein, H., Biochem. Z., 1913, li, 143; also Hober, H., 

 Physikalische Chemie der Zelle und der Gewebe, Jena, 4th edition, 1914, 460 fiE. 



