54 
ANNE M. LUTZ 
to have fourteen chromosomes of the usual size and one small one. 
The germ-cells were not examined. The significance of this 14+^- 
chromosome condition in offspring of 15-chromosome mothers was 
discussed in relation to the discoveries of Geerts, who showed in 191 1 
that seven of the twenty-one chromosomes of certain hybrids may 
fragment and degenerate during reduction, and of Gates and Miss 
Thomas ('14) who demonstrated that one of the fifteen chromosomes 
of 0. lata and certain /a/a-like forms may sometimes behave in a 
similar namner. 
In the paper just referred to, Gates and Miss Thomas announced 
the precise somatic chromosome number of 21 plants falling under 
the heads of 0. lata, 0. semilata and various lata-Yike forms. The 
authors found that "all without exception contained 15 chromosomes" 
and have discussed many new and interesting features "in connection 
with the behaviour of the extra chromosome and the phenomena of 
degeneration." Their researches appear to have led them to conclude 
that the presence of the extra chromosome in 15-chromosome offspring 
of 14-chromosome forms is invariably associated with lata or /a/a-like 
characters in the soma of the mutant. Later Gates ('15a, pp. 147-148) 
described a 15-chromosome mutant which he showed had a few 
characters in common with 0. lata and many others which were quite 
unlike those of the latter form. It appears, however, that he re- 
garded this mutant as a /a/a-like form, since nowhere in this work has 
he intimated that the discovery of 15 chromosomes in 0. incurvata 
has modified his previously expressed views concerning the relation 
of lata characters to the extra chromosome. In March of the same 
year de Vries ('15a, p. 187) described two types of offspring, besides a 
mutant which Stomps had obtained from 0. biennis semigigas pollinated 
without castration by pure biennis. One of the two types, represented 
by 8 individuals, had 15 chromosomes and he calls attention to the fact 
that while these plants had the same number of chromosomes as 
0. lata, they had none of the characters of the latter form. In December 
following Gates ('15&) recognized the fact that his mutant 0. in- 
curvata is quite different from 0. lata, as is also the 15-chromosome 
form which de Vries reported. He adds: "Hence we may say that 
whenever a germ cell having 8 chromosomes fertilizes a normal germ 
cell a new form is produced, though what its characters will be depends 
upon various circumstances which need not be considered here. One 
of the most important of these factors is probably the peculiar com- 
