174 



HAROLD H. PLOUGH 



TABLE 13— Continued 



Hatched at 31 °C., bred at 22°C. Nos. 428-437 



November 13. 

 November 15. 

 November 17. 

 November 21. 

 November 23. 

 November 25. 

 November 28. 

 November 30. 

 December 2. 

 December 5. 

 December 8. 



53 



%} 2 « 



83 

 59 

 104 

 65 

 70 

 81 

 75 

 41 



Returned to incubator on tenth day. Nos. 428, 429, 430, only 



November 23. 

 November 28. 



187 

 106 



The results given in these two tables are brought out much more 

 clearly when put in the form of a curve. Such curves for both 

 of the crossover regions involved are given in figures 4 to 8. 



In all cases the horizontal series denotes successive days after 

 mating, while in the vertical series are ranged the percentages 

 of crossingover. In figures 4, 5 and 6 the results for both regions 

 in each of the series which received the same treatment are 

 shown in one figure. The correspondence in the form of the 

 curves is seen to be close, except in the later portion where the 

 numbers recorded are small. In figures 7 and 8 the values 

 for the same region in each of the two series are set against each 

 other. Each of these figures brings out what can be gained only 

 by comparing figures 4, 5 and 6 with each other, namely, the 



