Discussion. 



in the introduction, the two important theories of 

 nuclear function were stated: the theory of synthesis and 

 the theory of oxidati on. According to the former theory, 

 the non-nucleated cell is unable to construct, build up, 

 synthesize nev/ substances; while according to the latter, 

 it is more or less unable to oxidise the substances already 

 present. In reviewing the experiments here reported, it 

 is seen that they not only offer strong evidence for the 

 validity of the synthesis theory, but they constitute a 

 practical proof that the oxidation theory is not true. 



From the outset there has been no satisfactory evidence 

 in support of the oxidation theory. It was apparently suggest- 

 ed by some experiments reported by Jpitzer (18^7). Spitzer 

 obtained from various cells a preparation of nucleoprotein 

 which contained a small amount of iron and which had the 

 property of decomposing hydrogen peroxide. From this it has 

 been concluded not only that all nuclei contain iron, but 

 even that all nucleoproteins contain iron. The latter 

 statement is of course false, and the microchemical evidence 

 in support of the former statement fMacallum, 1892) is very 

 unsatisfactory. 'i'he presence of iron in the nucleus was 



From a very pure preparation of the sperm heads of the 

 Great Lakes Whitefish, the author was unable to find a trace 

 of iron in 0.5 gram of the dry material by the sulphocyanide 

 test. The ashing was done in the electric muffle and by 

 Neumann digestion, so that there was no question of "mas]:ed" 

 iron. Unpublished. 



(62) 



