242 SIDNEY I. KORNHAUSER 



strepsinema. Finally in the later strepsistene stage, when the 

 chromatic spherule is given off, the y-element stains as deeply 

 as the two x-elements. In crystal violet + alizarin the y-element 

 is purple, and the xx-element brown with small purple granules 

 in it; whereas the nucleolar sphere of the late strepsinema is 

 deep purple. In methyl green + acid fuchsin, the y-element is 

 red, and the xx-element green. As the two fuse, in stages 

 corresponding to figures 25 and 26, the y-element gradually loses 

 its red color and becomes green, while the extruded nucleolar 

 spherule is a deep red. We must, I believe, assume that the 

 extrusion of this nucleolar spherule is in a vital way connected 

 with the change in " stainability " of the y-element. 

 v The twelve chromosomes of the primary spermatocyte meta- 

 phase (Plate XXV, figs. 28, 29) are so widely separated that, in 

 lateral views with very high magnification, one may focus sharply 

 on each element in the spindle. Good lateral views of the xxy- 

 hexad may be obtained not only in metaphase plates (figs. 30-33) 

 but also in anaphase stages (Plate XXVI, figs. 37, 38). Figure 

 34 (Plate XXV) shows the twelve elements of the metaphase plate 

 viewed laterally, the chromosomes of the several foci being here 

 transposed into a single row from the camera lucida drawing. 

 The hexad is on the extreme right. Figure 35 represents a 

 corresponding stage, but taken from a smear slide. The contents 

 of the cell were so spread out that a single focus displayed 

 all the chromosomes with no overlapping. In the smear slides 

 the chromatic elements appear smaller but retain all the features 

 seen in sections, and offer a very good check upon the latter. 

 The attachment of the y-element and the xx-element seems 



fy] r y i 



to be either terminal { x [ or lateral < > . Various arrange- 



IxJ 



ments of the elements taken from metaphases and anaphases are 

 seen in figures 30-38. Figure 36 (Plate XXV) shows seven 

 separate xxy-hexads, the y-element in all cases being uppermost 

 in the figures. 



In the first meiotic division (Plate XXVI, figs. 37-41) the 

 y-chromosome passes to one pole and the double x-chromosome 



