I. W. BAILEY 525 



In view of these and similar investigations, it might have been 

 expected a priori that the large, elongated, undifferentiated cells of 

 the lateral meristem or cambium, which in certain plants attain a 

 length of more than 10,000 micra and a volume of 10,000,000 cubic 

 micra, should contain more than one nucleus each. Such is not the 

 case, however, in any of the somewhat extensive series of gymno- 

 sperms and angiosperms that I have studied. Nor do the initials 

 contain abnormally elongated, giant nuclei, such as have been de- 

 scribed and figured by Molisch for highly specialized tissue cells of 

 certain monocotyledons. Each initial contains a single nucleus, which 

 is centrally located and retains this position during the processes of 

 growth and cytokinesis. 



It is evident, accordingly, that there is a very much greater varia- 

 bility in the size of meristematic cells in plants than was suspected 

 by Sachs or Strasburger, and that in elements of this type the nucleus 

 may extend its "energizing" influence to a distance of several thousand 

 instead of a few micra.^ 



The Relation between Cell Size, Nuclear Size, and Chromosomal Mass. 



Strasburger's measurements led him to believe that there is a close 

 correlation between cell size and nuclear size in the meristematic 

 tissue of plants, a conclusion that was strongly supported by the 

 experimental investigations of Gerassimow. The importance of this 

 relation between cell size and nuclear size was further emphasized 

 by Hertwig, and by Boveri, who endeavored to prove that "The 

 size of the larval cells is a function of the quantity of chromatin 

 which they contain, and the volume of the cell is in direct proportion 

 to the number of chromosomes." The subsequent painstaking and 

 detailed investigations of a number of zoologists have indicated that, 

 although in general large cells tend to have larger nuclei than small 

 cells, the nucleocytoplasmic-relation is not invariably a constant and 

 self-regulating ratio. In many animals, it fluctuates within rather wide 

 limits, not only as between different tissues, but even in embryonic 



® Sachs considered that the conditions in large animal eggs strengthened 

 rather than weakened his case, since these highly specialized, yolk-containing 

 cells are "inactive" until "energized" by numerous nuclei. 



