258 
C. F. TT. MEEK. 
must ask if the relationships between the lengths observed- 
can be correlated with those of other phenomena. 
Now the length of the spindle is evidently not connected 
with the volume of chromatin in the equatorial plane. I have 
shown in an earlier paper that the volume of chromatin in the 
metaphase is the same in the spermatogonial and primary 
spermatocyte mitoses ; whereas it is reduced to one half in the 
secondary spermatocyte. If correlation is to be established, 
we must accordingly find the same spindle length in the 
metaphase of the two first-named mitoses, and a different 
spindle length in the last. We find, however, that the length 
of the spindle is not the same in any two of these metaphases. 
Furthermore, it is evident that the spindle length is not 
connected with the number of chromosomes present; for the 
number of chromosomes composing the spermatogonial com- 
plex is double that composing the complexes of the primary 
and secondary spermatocytes. The length of the spindle at 
the conclusion of the metaphase cannot therefore be correlated 
with the chromatin of the cell. 
Let us now ask if the spindle length can be correlated with 
the cytoplasm. We know that no growth or resting stage 
occurs between the primary and secondary spermatocyte 
divisions, and that consequently the volume of the cell in the 
second must be half that in the first. Now the ratio between 
the radii of two spheres of which the volume of one is equal 
to twice that of the other is 1'2G : 1*00. And this is almost 
exactly the ratio between the lengths of the spindle found for 
these two metaphases; for the lengths found are 10*4 and 
8*1 fi, and — 
10-4 : 8*1 : : 1*28 : 1*00. 
If, therefore, inaccuracy of measurement is responsible for 
the slight difference between these ratios, the length of the 
spindle at the conclusion of each spermatocyte metaphase 
seems to be proportional to the radius of a s]Dhere equal in 
volume to the cell. 
We will now consider the secondary spermatogonial spindle. 
The length found for this mitosis at the stage w4th which we- 
