300 
R. A. HARPER 
development of the individual so far as they have been carried do however 
show clearly some tendency to the maintenance of more or less definite mass 
relations between chromosomes, nucleus, and cytoplasm — that is to the 
maintenance of a sort of mass equilibrium between the parts of the poly- 
phase cell system. The data as given would indicate a higher degree of mass 
constancy in the chromosomes than in the nucleus as a whole and in the 
nucleus than in the cell as a whole. 
The rather cataclysmic features of the early embryonic periods of de- 
velopment do not obscure entirely the tendency to constancy in the or- 
ganization of the cell as a whole. Such elemjents as cell polarity based on 
the space relations of nucleus, centrosome, and cytoplasmic mass, the rela- 
tive shape and position of special masses of food reserves, etc., all tend to 
remain constant or to change by slow progressive transformations and 
modifications. 
In eggs and macrospores overloaded with large masses of yolk or starch 
as temporary food reserves, the obvious tendency is to regain the balance 
between nucleus and cytoplasm normal for the cells of the given species in 
its adult form. A wider range of data in this whole field of the size relations 
of the various cell constituents is needed as a basis for the further develop- 
ment of the conception of the cell as a complex of colloidal systems. 
Farmer's results on two series of fern varieties are not consistent as to 
the relation of chromosome number to cell size, though for the lady fern 
series Strasburger's ratio that the diameter of the nucleus is to that of the 
cell as 2 :3 holds good. As Farmer notes, however, the small size and large 
number of chromosomes in the ferns make them unfavorable material for 
such studies. 
The evidence is certainly clear that the polarity and the mass relations 
of the parts of the cell, chromosomes to nucleus, and nucleus to cytoplasm, 
are in some degree specific, as is also the tendency to return to the norm for 
these relations when they have been disturbed. The further development 
and refinement of these concepts is of much importance for our conceptions 
of cell organization and for the transition from the old viewpoint that 
protoplasm as a substance has a specific structure to the conception that 
the fundamental organization of living material is expressed in the structure 
of the cell. 
The attempts to recognize plasmodia, coenocytes, syncytia, etc., as 
protoplasmic rather than cellular are, it seems to me, superficial and mis- 
leading. The old attempts to solve the problem of protoplasmic behavior 
by the assumption that it is composed of physiological units, biophores, 
determiners, plasomes, pangens, etc., and the newer conception that its 
essential elements are unit factors, are, it seems to me, being merged in the 
conception that the structure of protoplasm is the structure of the cell as 
an orga lized system and itself the unit in all the complex interactions by 
which the egg develops into the specialized and differentiated many- 
celled organism. 
