170 CHARLES W. METZ AND JOSE F. NONIDEZ 
Probably the density of the stain or degree of extraction has 
a good deal to do with the appearance or non-appearance of the 
duahty in these telophase nuclei, but there can be no doubt that 
the union is very intimate. In this relation the chromosomes 
pass (fig. 9) into the succeeding stage in which they lose their 
staining capacity to a much greater extent, as they enter the 
growth period. A careful scrutiny of the late telophase nuclei 
reveals very little indication of a spinning-out process or a net- 
work formation, except that due to the linin. The chromosomes 
appear simply to fade out through loss of color, while retaining, 
approximately, their form and position (fig. 9) . 
It is probable that the above account should not be restricted 
to the final spermatogonia, but should apply to all of the sper- 
matogonial telophases. The evidence points consistently in 
that direction (Metz, '16), but we have not been able to make 
sure of the point in the species under consideration. 
THE EARLY GROWTH PERIOD; STAGES A AND B 
Following the final spermatogonial telophase there is a very 
brief period during which relatively little chromatin is visible 
in the nucleus, as indicated by figure 10. This stage, which may 
be called stage a, is also characterized by the appearance of a 
small nucleolus, as shown by the figures. The nuclei of this 
period, together with those of the telophase just preceding, are 
the smallest to be found in the testis and cannot be confused 
with those of any other stage. 
Apparently our stage a corresponds to ^Montgomery's stage 
a in the Orthoptera and Wilson's stage a in the Hemiptera (see 
below). So far as we can determine, it is structurally similar 
to the early resting stage of the spermatogonia. The stage is 
so brief that it is only represented by a few scattered groups of 
cells at the border 'between the final spermatogonia and the 
clearly marked region in which the next stage (stage b) is 
represented. 
Adjacent to the nuclei of stage a (fig. 10) are others only slightly 
larger in which the chromatin becomes progressively more deeply 
stained and condensed, revealing the outline of the chromosomes. 
