1 6 DYNAMICS OF LIVING MATTER 



of facts which seem to harmonize with the idea that the nucleus is the 

 main oxidizing organ of the cell. Processes of regeneration demand 

 oxygen. Nussbaum* has shown that if an Infusorian be cut in such 

 a way as to divide it into two pieces, one containing the nucleus, and 

 one without any nuclear matter, only the former is capable of regenerat- 

 ing the lost parts. The other piece lives but a comparatively short 

 time and is not capable of regeneration ; it dies under symptoms which 

 are rather similar to death from lack of oxygen. 



Ralph Lillie t tried to test the idea that the nucleus is the main oxi- 

 dizing organ with the aid of staining substances which diffuse into the 

 cell, and change color when they are oxidized. He worked with the 

 cells of the blood, the liver, and the kidneys of frogs, and found that 

 the oxidation seems to occur most rapidly in the nucleus and on its 

 surface. He found, moreover, that the oxidations were most rapid 

 in those organs and those regions of organs where the nuclei were 

 densest. 



It has been noticed that if cells containing chlorophyll are deprived 

 of their nucleus, they keep alive longer if exposed to the light than if 

 kept in the dark. This may be connected with the fact that in the 

 light the chlorophyll is capable of liberating the oxygen from the CO 2 . 



It is stated, as a rule, that the role of the oxygen is to supply the 

 energy for the production of heat and of mechanical work, but it is 

 evident that this statement does not take into consideration the fact 

 that sessile plants, in which the loss of heat does not need to be com- 

 pensated by a production of heat, and in which no energy is spent in 

 mechanical motion, are in need of oxygen and possess oxidases. With 

 the exception of a limited number of anaerobic bacteria, the statement 

 can be made that oxidations and the presence of oxidases is a general 

 characteristic of living matter. There are, however, other vital processes 

 which are more general than those of locomotion and heat production, 

 which also require oxygen, i.e. cell division and growth. Pasteur made 

 the fundamental discovery J that with lack of oxygen the yeast cells 

 continue to produce lively fermentations of sugar, - - in fact, Pasteur 

 stated that their fermentative action is more energetic than in the 

 presence of oxygen, - - but that they grow and multiply very little or 

 not at all. If, however, oxygen is added freely, the yeast cells multiply 

 and grow considerably, provided the necessary nutritive salts are 

 present. According to Hoppe-Seyler and Duclaux, the absence of 

 oxygen favors the formation of the catalyzer for the alcoholic fermenta- 



* M. Nussbaum, Arch, fur mikroscop. Anatomic, Vol. 26, 1 886. 

 t Ralph Lillie, Am. Jour. Physiology, Vol. 7, p. 412, 1902. 

 \ Pasteur, Etudes sur la Iricre, Paris, 1876. 



