310 



INHERITED LINKAGE VARIATIONS 





some had been reconstructed by crossing-over. Table 4 presents the 

 results from these two cultures. The combined data from tables 1, 

 3, and 4 are summarized in table 5. Figure 1, second line, is a map 

 based on this table. 



Table 4. — Tests of females with one reconstituted Nova Scotia chromosome. 



0.0 



00 



p- 



yg 



b 

 — I — 



37.9 441 55.9 



S'b pr ■vgc sp 



c 



— f— 

 64.0 



sp 



94.2 



0.0 02 1.3 1.4 



0.0 0:5 



vgc sp 

 b pr .-.-• 



-\ +■■■ 



42.4 48 6 ■■; 



50.2 50.3 



y^ 



13.4 21.0 



t— 



0.0 



g'b pr c sp 



06 0.'2 3:1 3.2 

 S*. b pr 



T 



47.8 



0.0 0.3 0.4 



b pr 

 + ■ 



sp 



38.2 41.7 



63.2 



I 



Fig. 1. — Maps based on table 25. The first corresponds to the first column of the table, 



the second to the second column, etc. 



The star black plexus data given here show an unexpectedly high 

 percentage of crossing-over between black and plexus. The data 

 should perhaps not have been included, as there is reason to believe 

 that another gene affecting crossing-over may have been present (see 

 below, p. 324). For this reason plexus has not been entered on 

 the map in figure 1. 



The black balloon percentage (6.1) is unexpectedly higher than 

 black speck (1.1). As may be seen from the account here given by 

 Bridges and Morgan, speck and balloon certainly give less than 1 per 

 cent crossing-over in ordinary flies. Unless some complication is 

 here present, balloon must be to the right of speck, and the speck 

 balloon region must give more crossing-over than usual in the presence 

 of a Nova Scotia chromosome. 



