n 



Fig. 4.1 — Camera lucida sketch at pachynema of bivalent consisting of one normal and one 

 abnormal chromosome 10. Note the dissimilarity in chromomere pattern in the distal one- 

 sixth of the long arm. The identical chromomere pattern found in the remainder of the 



chromosomes is not figured here. 



Fig. 4.2 — Anaphase I of cell illustrated in Figure 4 of Plate I. Some of the disjoining dyads 

 are normal appearing while others have active neo-centric regions. 



Fig. 4.3 — Metaphase I with eleven dyads. Five of the dyads have precocious neo-centro- 

 meres at sub-terminal portions of their long arms. 



Fig. 4.4 — Anaphase II of cell illustrated in Figure 7 of Plate II. In some of the inverted 

 V-shaped monads the true centric regions are attracted toward the opposite pole. 



