320 THE ANIMAL CELL. 



as in most animal cells, does not exist. But it is generally supposed 

 that a meshwork of fine fibrils pervades the protoplasm, and that in 

 the meshes a more liquid portion is contained. This is termed the 

 hyaloplasm, in contradistinction to the more solid spongioplasm. In 

 some forms the protoplasm is apparently perfectly homogeneous, while 

 in others it is studded with numerous granules of variable size, which 

 execute more or less active oscillatory movements, which are spoken 

 of as the molecular movements of Brown. 



The reaction of the protoplasm is alkaline, while the nucleus 

 apparently contains no free alkali. This may be shown by staining 

 dried blood films with a solution of acid erythrosin in chloroform, 

 when it will be seen that the body of the cell is colored a bright red, 

 while the nucleus is not stained. The most intense reaction is 

 obtained with the protoplasm of the so-called lymphocytes. 



The granules which are found in certain forms of leucocytes are 

 apparently of an albuminous nature. According to their affinity for 

 acid, basic, or neutral dyes, they are termed oxyphilic, basophilic, 

 and neutrophilic, respectively. Fatty, mineral, or pigment granules, 

 which may be found in other animal cells, are usually not seen in 

 leucocytes. In the eosinophilic leucocytes, however, the presence of 

 iron can readily be demonstrated by microchemical methods. In 

 another form it seems to be present in all varieties of cells, and is 

 especially abundant in the nuclei. 



In the mineral ash we find potassium, sodium, calcium, magne- 

 sium, phosphorus, and chlorine, and it is to be noted that, in 

 contradistinction to the animal fluids, the cell contains a relatively 

 larger amount of potassium and phosphorus, while sodium and 

 chlorine are more abundant in the fluids. That the phosphates are 

 of prime importance in the life of the cells is now definitely 

 established, and Loew showed that in the spirogyra, for example, 

 growth and cellular division are greatly interfered with by their 

 absence. The importance of the phosphates is without doubt con- 

 nected with the presence of the nucleins in the nuclei i. e., of 

 albuminous substances which, as we have seen, contain a relatively 

 large amount of phosphorus in organic combination. 



The protoplasm of the cell is very rich in water, and, in addition 

 to small amounts of mineral salts, consists essentially of albumins. 

 Some of these are albumins proper, but the greater portion is 

 represented by substances which* belong to the nucleoproteid 

 group. It appears, moreover, that the traces of serum-albumin and 

 globulin which are present do not represent integral constituents of 

 the living protoplasm, but are merely to be regarded as food-stuffs, 

 or possibly even as decomposition-products of the protoplasmic 

 molecule. 



Of other constituents of the protoplasm, lecithin is the most 

 constant. In addition, we find protagon, glycogen, cholesterin, and 

 in dead cells also paralactic acid, to which the acid reaction of dead 

 protoplasm is due. 



