of Phosphorus in Animal and Vegetable Tissues. 477 



holding confirms the view which I advanced seven years ago,* that 

 both are primarily derived from the nuclear chromatin. 



The deeper reaction for phosphorus which is obtained in that part 

 of the pancreatic cell immediately adjacent to the lumen, may be 

 due to ferments dissolved in the cytoplasm at this point or to a 

 phosphorus-holding substance derived from the zymogen at the same 

 time the ferments are formed. 



A diffuse reaction for phosphorus, slow in appearing, was obtained 

 in the cytoplasm of liver cells of dog and man. These cells also 

 frequently contain abundance of inorganic phosphates whose presence 

 may render the demonstration of the organic compound difficult. 



I have been unable to determine whether organic phosphorus com- 

 pounds are present in the cytoplasm of the renal cells, for in the dog 

 and human subject these cells are rich in inorganic phosphates which 

 are difficult to extract, and, consequently, obscure the reaction for 

 the other compounds if these occur here. 



Mr. F. H. Scott, who is at present working on the micro-chemistry 

 of nerve cells, has found that Nissl's granules also give a distinct 

 reaction for phosphorus. He has also found that the substance 

 forming the granules does not digest in artificial gastric juice. 

 Mackenzief had previously found that these granules contain 

 " masked " iron. They stain like chromatin. These facts lead one 

 to conclude that the substance of the granules is a nucleo-proteid. 



A feeble reaction for phosphorus has been obtained in the axis 

 cylinders of medullated nerves from which the lecithin was extracted. 



In the muscle fibres from the chelae of the crayfish a deep phos- 

 phorus reaction was obtained in the dim bands and in the beadlets 

 which constitute Dobie's line, while no reaction occurred in the 

 lateral discs of Engelmann. The phosphorus-holding substance is 

 coterminous with the anisotropous element. The phosphorus demon- 

 strated is not due to presence of lecithin, for this was wholly ex- 

 tracted from the preparation before it was treated with the nitric- 

 molybdic reagent, and it was not due to inorganic phosphates, for the 

 reaction did not come out, except very feebly, during the first twenty 

 minutes. 



In the striated muscle fibres of Amphibian larvae the iron-holding 

 substance appears to be also limited in its distribution, as it was 

 found only in the dim bands, Dobie's line giving no evidence of its 

 presence, perhaps because this structure in Amphibia is too minute 

 to permit a proper determination of this point. In my experiments 

 on crayfish muscle both the dim band and Dobie's line appear to give 



* ' Trans. Can. Inst.,' vol. 1, p. 247, 1891. 



f " Investigation in the Micro-chemistry of Nerve Cells," ' Brit. Assoc. Report,' 

 1897, p. 822. 



I ' Quart. Journ. Micr. Sci.,' vol. 38, p. 220. 



2 N 2 



