88 
ANNE M. LUTZ 
While, as we have seen, de Vries has shown that 0. scintillans, when 
selfed or polHnated by O. Lamarckiana, behaves in much the same way 
as 0. lata under similar conditions, statements concerning the chro- 
mosomal combinations resulting from these operations must be 
wholly speculative since the num*bers of chromosomes present in 
0. scintillans and its ohlonga offspring are unknown. However, if 
scintillans has 15, as is probable, there is much evidence to indicate 
that 7- and 8-chromosome female gametes, capable of functioning, 
and, as a rule, only 7-chromosome male gametes, capable of function- 
ing, are produced by this form,^^ whether ohlonga has 14 or 15 chro- 
mosomes. That only 7-chromosome male gametes are produced which 
behave in every way like the 7-chromosome male gametes of 0. La- 
marckiana is clearly indicated by the fact that while 0. scintillans, 
selfed, and 0. scintillans X 0. Lamarckiana produce 0. scintillans, 
O. Lamarckiana and 0. ohlonga, 0. Lamarckiana X 0. scintillans 
yields 100 percent 0. Lamarckiana (de Vries, '13). A noteworthy 
peculiarity in the behavior of O. scintillans is the relatively large 
number of offspring of one type derived from the mutant, selfed, and 
pollinated by 0. Lamarckiana, which display neither the characters 
of 0. scintillans nor of O. Lamarckiana, but of the mutant, O. ohlonga. 
This indicates either that a relatively large percentage of the offspring 
resulting from 8+7 unions fail to reproduce the characters of the 
mutant parent, or that a relatively large percentage of those derived 
from 7+7 unions fail to display the characters of 0. Lamarckiana. 
The behavior of 0. hipartita and of 0. suhlinearis (if the latter has 
15 chromosomes, and it is probable that it has) indicates that all, or 
nearly all, of the gametes of one sex which are capable of functioning, 
contain 7 chromosomes, while a portion of those of the other sex 
contain 7 and the remainder 8. The same may be said of 0. semilata 
Gates if the offspring which Gates refers to as "forming a continuous 
28 In the case of 0. lata and other forms to be discussed in this report, it will be 
understood that the writer does not exclude the possibility of other gametes being 
formed occasionally in addition to those enumerated — gametes having fewer than 
7, or more than 7 or 8 chromosomes. For instance, as earlier stated, it is conceivable 
that 6-chromosome gametes may function in union with 8- or 8+-. It is possible 
that 9-chromosome gametes, capable of functioning, may be produced occasionally 
by 14- and 15-chromosome forms, particularly the latter, and we know that there is 
much evidence to show that 14-chromosome gametes are sometimes produced by 14- 
chromosome forms (possibly also by 15-) and 15-chromosome gametes by 15-chro- 
mosome forms. 
