506 STUDIES IN GENERAL PHYSIOLOGY 



energetically. The majority of investigators believe that 

 oxygen is activated in the tissues, and that in this process 

 certain substances act catalytically which, after Traube, we 

 will call "oxygen carriers." It has been possible to extract 

 these oxygen carriers from the cells and to show that in this 

 condition the oxygen carriers are still able to bring about 

 those oxidations which are characteristic of living matter. 



The most valuable discovery in this direction was undoubt- 

 edly made by Spitzer. 1 Spitzer has shown that those sub- 

 stances in extracts of tissues, which favor the transfer of 

 oxygen (oxidation ferments) belong to the group of nucleo- 

 proteids. The nucleoproteids are typical substances of the 

 nucleus. All these nucleoproteids contain iron. Now, we 

 know that iron salts are especially adapted to accelerate 

 oxidation. There is no reason to doubt that what is true 

 for the aqueous extracts of the cells holds also for the 

 nucleoproteids of living cells. Macallum has proved the 

 existence of iron in the chromatin substance of the cell 

 nuclei. The work of Spitzer, therefore, renders it probable 

 that the nucleus is the organ of oxidation in living matter. 



We will now see whether the behavior of cell fragments 

 without the nucleus corresponds to this assumption. Verworn 

 describes the changes which occur in the pseudopodia in 

 these cases as follows : In the pseudopodia of an enucleated 

 piece of Orbitolites droplets are formed which, in part, flow 

 together into larger drops. The connection between the 

 individual drops disappears. "Finally, after about five to 

 seven hours the central portion forms a round lump without 

 pseudopodia, around which are scattered a number of larger 

 and smaller globules, drops, and spindles of protoplasm/'' 

 Verworn in adopting and misunderstanding the view of 

 Berthold has developed a theory of amreboid movements 



1 PflUgers Archiv, Vol. LXVII (1897), p. 615. 



2 VEKWOEN, Pfliigers Archiv, Vol. LI (1892). 



