PLATE 2 



EXPLANATION OF FIGURES 



20 to 31 From Tropidolophus. 



20 Polar view of spermatogonia! complex. 



21 to 24 Polar views of metaphase groups in first spermatocyte. The acces- 

 sory chromosome is centrally placed and is irregular in outline, as in Hippiscus. 



-25 Lateral view of first spermatocyte metaphase complex with the members 

 extended in rows. At a is a ring, e?i face; at 6 a lateral view of a ring with the 

 contrasynaptic ends also drawn out. 



26 to 30 Polar views of first spermatocyte metaphase complexes. 



29 A complex, six members of which are plain rings. A photomicrograph of 

 this group is shown in figure 110 and in figure 140 appears a photograph of wax 

 models of the group arranged as in the cell. Similar rings are seen in the remain- 

 ing polai views, but in addition there are others, evidently rings, which are not cir- 

 cular in outline but show various enlargements on the other side. These modifi- 

 cations are due either to a simple divergence of the contrasynaptic ends or to a 

 further extension of these so as to complete a secondary ring at right angles to the 

 first. 



31 Polar view of second spermatocyte metaphase with a complex of 12 chromo- 

 somes. The uniformity in shape of the chromosomes in this cell generation is 

 well shown. 



732 



