PLATE 5 



EXPLANATION OF FIGURES 



59 to 76 From the unidentified Stenobothrus-like form described in the text. 



59 to 62 Polar views of spermatogonia! metaphase. Of the twenty-one 

 chromosomes (fig. 60 shows but twenty) twelve are the common rod-like forms 

 with terminal attachment and the remaining nine have either median or submedian 

 attachments. 



63 Lateral view of first spermatocyte metaphase showing four ordinary shaped 

 tetrads, a ring placed in the plane of the spindle axis, and, at the left, another such 

 an element, but with the synaptic ends drawn out and bent to form a ring in the 

 plane of the equatorial plate. 



64 Various first spermatocyte chromosomes in metaphase or early anaphase. 

 Tetrads formed from spermatogonial chromosomes with non-terminal fiber attach- 

 ment shown at a, b, c, d, g, and h. At e and/ are others produced by union of sper- 

 matogonial chromosomes with terminal fiber attachment. 



65 Lateral view of the first spermatocyte metaphase showing four chromo- 

 somes of ordinary type and two with non-terminal fiber attachment. 



66 Lateral view showing conditions as in figure 65 and the accessory chromo- 

 some which has a median attachment instead of terminal as in most species. 



67 Polar view of first spermatocyte anaphase. 



68 to 76 Polar views of second spermatocyte metaphase. The same series 

 of sizes and forms apparent in the spermatogonium may now be seen in the grand- 

 daughter cells. 



738 



