Hatai, Spinal Ganglion Cells of Rat. 



471 



values of the two diameters thus obtained were multiphed together 

 and the square root of the product was called "calculated diam- 

 eter" of the cells and nuclei. Of course every section of a cell 

 which possessed a distinct nucleus and nucleolus was measured 

 from the nine sections and altogether 1108 such cells were found. 

 The 1 108 cells and nuclei thus measured were arranged according 

 to the magnitude of the "calculated diameters" and the fre- 

 quencies of the variates were determined as shown in the corre- 

 lation table (see p. 490). For grouping the variates I have 

 selected 2 micra as the unit for the cell-body and 0.65 of a micron 

 for the nucleus. As will be seen later, small differences in the 

 value of the unit do not produce any significant change in the 

 final results, and therefore it is advisable to select some integral 

 number for convenience in computation. 



ANALYTICAL CONSTANTS AND FREQUENCY DISTRIBUTION, 



I shall first discuss the frequency distributions of the cell-bodies 

 and nuclei. The fundamental analytical constants necessary 

 for such discussion are given in the following table: 



TABLE I. 



It has been shown by Pearson ('05) that in order to fit a 

 given distribution of frequency to a Gaussian probability curve 



