CONFIGURATIONS OF BIVALENTS OF HYACINTHUS. 



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configurations (Diagram I.). Three of these are shown in Fig. 

 i, where the cross (L 2 ) is near the center, two single rings with 



DIAGRAM i. Numbers of different configurations of large bivalents. The cross, 

 single ring and V, and figure of 8, have one node; while the ring and two V's, the 

 double ring and V, and the triple ring have 2 nodes. 



double V's are on the right (Li and L 4 ), and a double ring and 

 V on the left (L 3 ). Four forms in the late prophase are shown 

 in Fig. 2. They are: (a) the ring and V; (b) the double ring 



FIG. 2. Four camera drawings of large bivalents at the late prophase. (This 

 stage is difficult to obtain.) 



and V; (c) the ring and two V's; and (d) the figure of 8. The 

 cross and the triple ring were not found free, the bivalents being 

 usually clustered at this stage. Several configurations are drawn 

 in Fig. 3. It may be specially noticed that the four examples of 

 the cross shown in Fig. 3 have the junction in different positions 

 with regard to the chromosome ends. The cross in the middle 



