1894,] Chemico-Physiological Discoveries: The Cell. 105 
of primary importance for the life and development of the 
animal cell, as no doubt also are the earthy phosphates, 
although we can hardly formulate how they exist in the cyto- 
plasm unless it be in close union with the proteids or nucleo- 
albumins of the cell, for which we know they have a strong 
affinity. Again, it is to be remembered that the ash of all 
cells shows the presence of a certain amount of ferric oxide. 
This, however, does not come from ordinary iron salts present 
in the protoplasm, but the iron appears to exist in some pecu- 
liar organic combination, apparently united to carbon. It is 
especially to be noted as a component of so-called iron-con- 
taining nucleins, or nucleo-albumins. 
It is thus seen that proteid matter in some one or more 
forms, mostly as nucleo-albumins, constitutes the great bulk 
of cytoplasm, and the typical anabolic product of the living 
cell is unquestionably represented by a molecule, or molecules, 
in which proteid matter occupies a prominent place. “But 
that the albumin molecule is alone the bearer of life and all 
the other constituents of the protoplasm its satellites we cer- 
tainly cannot affirm.” (Kossel) 
Between the cytoplasm and the karyoplasm there is very 
little constant difference. The one typical constituent of the 
cell nucleus, however, is nuclein or one of the bodies of that 
group. It is important to note in this connection that such 
examinations as have been made show that the primary con- 
stituents of the cell may be located in the nucleus in great 
part, or they may be evenly distributed through both cyto- 
plasm and karyoplasm, or indeed they may be almost wholly 
wanting in the nucleus, occurring only in the cytoplasm.’ 
This latter condition offers a ready explanation of the well- 
known fact that cells rich in nuclei and consequently contain- 
ing only a little cytoplasm, as the spermatozoa, are extremely 
poor in many of the primary bodies of ordinary cells. The 
one body, however, characteristic of the cell nucleus is 
nuclein. 
Cholesterin and lecithin are certainly common_to both cyto- 
plasm and karyoplasm, being found abundantly in cells rich 
‘Kossel. Verhandlungen d. physiol. Gesellschaft zu Berlin, Feb’y, 1890. 
