28S 



THE AMERICAN NATURALIST [Vol. XLV 



Various observers have pointed out the predominant 

 part played by the nucleus in intra-cellular oxidations, 

 operating apparently by means of oxidases. R. S. Lillie 

 has shown that in the indophenol reaction the colored 

 oxidation products in such cells as red corpuscles, and 

 those of liver and kidney, are deposited mainly in and 

 around the nuclei. He further points out 2 that certain 

 ferments exhibit the properties of nucleoproteids and 

 that they are apparently concerned with later chemical 

 changes in the protoplasm chiefly oxidative in nature. 

 As far back as 1895 Wilson and Mathews"' showed that in 

 the first maturation division of the starfish egg much 

 chromatin is set free in the cytoplasm. In 1902 Conklin 4 

 called particular attention to the escape of nuclear 

 material into the cytoplasm upon dissolution of the 

 nuclear membrane in the egg of Crcpidula, remarking 

 further upon the large proportion of chromatin that 

 passes into the cytoplasm during every cell cycle, where 

 seemingly it plays some important part in the subsequent 

 changes of the latter. Likewise, F. R. Lillie, 5 in 1906, 

 pointed out that an important part in the development 

 of Chaetopterus is played apparently by the great quan- 

 tities of a " residual substance" set free from the ger- 

 minal vesicle. Lyon in 1904 showed a rhythmic parallel 

 between nuclear division and the production of carbon 

 dioxide by the cleaving egg. And Mathews 7 in 1907 sug- 

 gested as probable that the periodic disappearance of 

 the nuclear membrane during mitosis brought about a 

 distribution through the cytoplasm of oxidases which had 

 been synthesized in the nucleus. Wieman 8 in 1910 has 

 shown the existence of alternate phases of acidity and 

 basicity in the process of yolk formation in Leptinotarsa, 

 due to a succession of oxidation processes which occur in 



'Jour. Exp. Zool., Vol. V, pp. 379-428, 1908. 



'.four. Acad. Xat. Sri, )>hihi., Vol. XII, pp. 1-121, 1902. 



"Jour. Exp. Zool, Vol. Ill, pp. 163-268, 1906. 



« Am. Jour. Physiol, Vol. XI, pp. 52-58, 1904. 



7 Am. Jour. Physiol, Vol. XVIII, pp. 89-111, 1907. 



' Jour. Morph., Vol. XXI, pp. 135-216, 1910. 



