56 
ANNE M. LUTZ 
In the year following that in which the note was published concern- 
ing O. albida, it was announced that 15 chromosomes had been counted 
in two lata offspring of 0. lata X 0. gigas (Lutz, '09). These plants, 
of course, were not mutants, but it did not seem unreasonable to 
suppose that mutant lata would be found to have the same number of 
chromosomes as the hybrids. Gates, however, had repeatedly an- 
nounced 14 as the sporophyte number for 0. lata and the evidence 
produced seemed quite sufficient to support his claims. In a prelimi- 
nary note published in 1907^ he said (p. 260) : "The sporophyte number 
of chromosomes in 0. lata . . . is 14." Speaking of 0. lata in the 
detailed report which followed,^ he said (p. 92): "It has been deter- 
mined from a number of counts in the prophase that the sporophyte 
number of chromosomes . . ., is 14." (Italics not employed in the 
original.) Again, later in 1907'' (p. 9), "In 0. lata the count of chro- 
mosomes was made in the pollen mother cells and found to be fourteen. 
It has since been made in various somatic tissues of the flower, and is 
found to be constantly fourteen so far as observed. There has been 
no indication whatever that the number is ever higher.^' (Italics not 
employed in the original.) Again, on page 11, "Several plants of 
0. lata and the pure 0. Lamar ckiana have been examined, all having 
fourteen chromosomes." 
As earlier stated, the primary object of the Cold Spring Harbor 
studies of Oenothera, begun in 1907, was to ascertain whether or not 
each particular combination of somatic characters, such as that rep- 
resented by the type we know as 0. lata, for example, is associated 
with a definite, fixed number of somatic chromosomes; in other words, 
whether or not somatic chromosome number in Oenothera is constant. 
Years of careful study, by the writer, of the vegetative characters of 
plants from seedling to fruiting stage (never overlooking the importance 
of taking note of the slightest deviation from the combination repre- 
sented by the type) together with the precise determination of somatic 
chromosome number in over 200 individuals, established the fact that 
each combination of somatic characters is constantly associated with 
a certain number of chromosomes; in other words, that each type of 
plant has a definite, fixed number of chromosomes. It was therefore 
announced in "Triploid mutants" (Lutz, '12), and many times em- 
^ Gates, '07a. 
^ Gates, '07&. 
' Gates, '07^. 
