W. Koch and M. L. Koch 433 



Anatomical distribution and physiological significance. The protein phos- 

 phorus is largely associated with the nucleic acid of the nucleus. In the 

 nervous system it is also supposed to be associated with the Nissl sub- 

 stance, but this is still a doubtful matter. The accuracy with which we 

 can estimate nuclear material in the anatomical sense from such a figure 

 as the protein phosphorus is difficult to determine, as there are three 

 complicating factors. 



1. The possibility that the nucleus, as an anatomical unit, contains 

 other compounds besides nucleoproteins. 



2. The fact that nucleic acid itself may be associated with very widely 

 varying quantities of protein. 



3. The possibility that substances yielding a protein phosphorus frac- 

 tion may occur in the cytoplasm. 



Observations by Miescher 21 on the sperm, however, very strongly sug- 

 gest that protein phosphorus is largely associated with the nucleus, while 

 lipoid phosphorus is largely associated with the cytoplasm. 



As regards the water-soluble phosphorus, the principal point of interest, 

 just as in the case of the neutral sulphur, is its ratio to the protein or col- 

 loidal forms of phosphorus. Thus in a study on a lower plant form (Asper- 

 gillus niger] Koch and Reed 22 could demonstrate that under extreme con- 

 ditions, such as can only be realized with plant material, it is possible to 

 carry the growth processes to such a point that all the non-colloidal, 

 water-soluble phosphorus is converted into colloidal combinations. At 

 such a point the growth of the plant comes to a stop. 



The function of the inorganic phosphates in maintaining the neutrality 

 of protoplasm as suggested by Henderson 23 is also a point of interest, 

 although of less importance to the nervous system than to muscle tissue. 



Inorganic constituents. 



Chemistry. The inorganic constituents found in the nervous system are 

 the cations Na, K, Ca, Mg, Fe, and the anions Cl, SO 4 , P0 4 . 



In the method devised for this study the usual method of estimating 

 these constituents by the ash was abandoned on account of the fact that 

 by the process of ashing, the relation of cations to anions is profoundly 

 altered. As a result of this precaution, the interesting fact has been 

 clearly demonstrated that a large proportion of the cations, especially 

 sodium and potassium, occur combined with complex anions, sometimes 

 colloidal in nature. 



The work of Pike* 4 has brought to light the interesting point that in 

 the nervous system the sodium and potassium, more especially the latter, 



21 Miescher, F. : Hoppe-Seyler's Med.-chem. Unters., p. 452. 



22 Koch, W. and Reed, H. S.: this Journal, iii, p. 49, 1907. 



23 Henderson, L. J. : this Journal, vii, pp. 29-35, 1910. 



24 Koch, W. and Pike, F. H.: Journ. of Pharm. and Exp. Ther., ii, pp. 

 245-248, 1910. 



THE JOURNAL OF BIOLOGICAL CHEMISTRY, VOL. XV, NO. 3 



