MENDELIAN SEGREGATION - ll 
somes conjugate in pairs, as shown diagrammatically 
in Fig.5,b. The chromosomes then separate (Fig. 5,¢ 
and d) at the time of division of the cell, and one of the 
resulting daughter cells gets the chromosome bearing 
the vestigial, and the other daughter cell gets the 
homologous chromosome, bearing the long factor. 
Hence, there will be two kinds of eggs in the female 
and two kinds of spermatozoa in the male. When 
two such hybrid flies mate with each other, any 
JN 
rd ds val, 
nN “I 
a 4 
Fria. 5.—Diagram to illustrate in a heterozygous individual the con- 
jugation and segregation of the chromosomes during “reduction. 
sperm may meet and fertilize any egg. The possible 
combinations that result, and the frequency with 
which they occur, are shown in the next diagram 
(Fig. 6, and also in Fig. 3.) 
As shown in this diagram, a sperm bearing the fac- 
tor for long fertilizing an egg bearing the same factor 
produces a fly pure (homozygous) for long wings; 
a sperm bearing the factor for long fertilizing an egg 
bearing the factor for vestigial wings produces a hy- 
brid fly (heterozygous) that has long wings, since, as 
above, the long ‘‘dominates” the vestigial character. 
