28 BOTANICAL GAZETTE [JULY 
ana plants from the F, of O. lataxO. Lamarckiana (13), in which 
sometimes eight chromosomes pass to one pole and six to the other; 
but it may also occur rarely in the pure races. This matter was 
briefly discussed elsewhere (14). Assuming that the 14 chromosomes 
are in two similar sets of 7 each, and that homologous members of 
these sets conjugate except when there is a failure to pair, then when 
8 chromosomes go to one pole and 6 to the other, both members of one 
of the pairs must have gone to the same pole. This probably takes 
place in cases where such members were unconjugated, for the 
purpose, or at any rate, the result of the pairing is in ordinary cases 
that one member of every pair shall be distributed to each pole. If, 
while two members of one pair thus go to one pole, the second member 
of another pair goes to the other pole, we should have an equal 
numerical distribution of chromosomes, but one daughter group would 
be lacking both members of one pair and the other would be lacking 
both members of another pair. It is highly probable that such a 
distribution occasionally takes place, though it would be less common 
than the case, already proved, where the members of a single pair are 
unilaterally distributed. It should be borne in mind that such cases 
