Table 3. 4^th chromosome nondisjunction in males.

Paternal genotype	Wild type	WT+B
Normal
4	737	964
4th nondisjunction
44	0	1
0	0	3
Adjusted total	737	968
% diplo-4	0.0	0.1
% nullo-4	0.0	0.3
Total % 4th NDJ	0.0	0.4

Male WT+B flies were crossed to females bearing an attached 4^th chromosome. Their progeny displayed 0.4% 4^th nondisjunction, compared to 0.0% in wild type.