INEQUALITIES IN HOMOLOGOUS CHROMOSOMES 113 
place. This separation begins at the proximal ends of the pair 
and gradually moves along toward the distal ends (figs. A; to As). 
By the proximal end I mean that from which the spindle fiber 
springs and that which travels in advance toward the pole. 
The opposite, blunt end is the distal end. The proximal ends of 
the pair diverge, each through an angle of 90°; i.e., until they are 
180° apart (figs. As to As). The proximal ends now point in 
opposite directions, and the pair, thus attached at their distal 
ends, form a rod. In this condition the pair (tetrad) enters the 
first maturation spindle (fig. As). 
The defective tetrad, like the others, has gone through this 
process. But a portion of the distal end of one of the chromo- 
somes being gone, the chromosome cannot conjugate properly 
with its mate and so has a tendency to slip to one side when the 
tetrad reaches this stage, as figures 5 to 7, and E, to E; show. 
The normal conjugant (diad) finds at its distal end no correspond- 
ing portion in the defective mate with which to pair. The chro- 
mosomes were probably paired normally at the proximal ends 
and in all parts which are present, leaving the distal part of the 
larger normal member extending beyond the shortened distal 
end of the defective mate (fig. E.). In ‘the process of separation 
which follows conjugation the defective chromosome (diad) 
had its shortened distal end rotating on the side of the distal 
end of the longer, normal mate. When the diads had rotated 
apart 180° this shortened end was as a result out of line with the 
end of its longer mate (figs. E. to E;). This is the condition in 
which the defective chromosome of figures 5, 6 and 7 ¢ is seen. 
2, AN UNEQUAL PAIR OF ANOTHER TYPE OCCURRING IN 
ACRIDIUM GRANULATUS 
While working out the chromosomes in dividing ovarian 
follicle cells of the female individuals of Acridium granulatus, I 
found one animal which showed among its 14 chromosomes 
five long members (fig. 11) instead of four (the two 6’s and the two 
7’s). This puzzled me in my pairing of the chromosomes. The 
material was laid aside for the time. A few weeks later I found 
a male individual which showed in its first maturation divisions 
