

get several nuclei close together with the two elements in focus at the 

 same time, but most of these show at least two cells. Figure 11 is in 

 focus at the level of the upper part of the nucleus and shows the ac- 

 cessory extended as in figures 5 and 6. 



Figs. 16-20. — Photographs from smears on Lefevre's slide 30, showing 

 the late prohases of the first spermatocyte. The accessory is distinguished, 

 as Foot and Strobell point out, by having two halves lying side by side 

 without lateral extensions. There is no indication of a second plane of 

 division, as may easily be seen in figures 16 and 20. In figure 20 there 

 appear thirteen elements. 



Figs. 21-26. These are from smears, and show the chromosomes of the 

 first spermatocyte in metaphase. The great difference in the size of the 

 chromosomes, due to the variation in the extent of spreading, upon drying 

 may be judged by comparing figure 22 with figures 23 and 10. In figure 23 

 there are twelve elements, one much lighter than the others, which may be 

 interpreted as an unsually resistant plasmasome which has persisted much 

 longer than common. In all of these the accessory may be identified both 

 by its position and by the single plane of cleavage indicated. It has been 

 injured in the cell represented in figure 23, where it is seen next to the 

 plasmasome with one corner cut sharply off. 



Figs. 27 and 28. — Photographs of the first spermatocyte metaphase, 

 polar view, showing the typical arrangement of the chromosomes. The 

 accessory lies without the ring and the m-chromosome in the center. 

 These prints are from the same negative and show how it is possible to 

 vary the apparent size of structures even by printing. Wilson's section. 



Figs. 29-33. — Polar views of first spermatocyte metaphases from sec- 

 tions. In order to get several cells to show together the focus was shifted 

 during exposure in making photograph 31 so that the outlines are not 

 sharp. In figure 29 the accessory does not shov/, being just out of focus 

 in the lower cell. From these illustrations it may be seen that while 

 there is a general agreement in the arrangement of the chromosomes in 

 the equatorial plate, it may be modified in details. Wilson's sections. 



