118 Hayes. 
harvested and allows of topping plants by the usual farm practice, 
with the exception of those saved for seed. 
It.has been shown in a previous article, Hayes (:12), that the 
number of leaves per plant is a character which is little affected by 
environment. Thus, the mean for each of four inbred types grown 
at Forest Hills, Mass., on a well fertilized soil, at Bloomfield, Conn., 
on a heavily fertilized typical tobacco soil, and at New Haven, 
Conn., on a very light gravelly soil only moderately dressed with 
fertilizers, gave a variation from the average mean of the type of 
—+.8 leaves per plant. 
Data on two crosses are given in this article, but for convenience 
each cross will be separately discussed. 
Family (403 >< 401) Sumatra >< Broadleaf. 
The Sumatra parent had been grown under shade in Connecticut 
from seed inbred for several generations. 
The Broadleaf parent has been grown in the open in Connecticut 
since the early history of the tobacco industry and is of a very 
uniform type. 
The cross was made in Igog and in IgIO the parent types and 
F, were grown in New Haven. Inbred seed of the parents and Fy 
were grown in New Haven in IıgII and several large cultures of the 
F, generation were also grown in Bloomfield. In 1912 a later gene- 
ration of the parents and five F, generations from selected F, plants 
were grown in New Haven. Eight F, generations were also grown 
in Bloomfield. 
In Table r from left to right in separate columns are given the 
selection numbers, the year grown, the leaves of the parent plant 
when known, the range of variation, the number of plants counted, 
the mean value for number of leaves, and the coefficient of varia- 
bility, the two latter calculations being those of greatest value. 
There seems to be a gradual decrease for leaf number, and in 
1912 an increase of variability for No. 403, Sumatra. 
As the results of a count of leaf number for ıgII and 1912 are 
very similar being 26.5 +.ıı and 26.2+.12 respectively, it may 
be possible that the mean in IgIo which was 28.2-+.08 is some- 
what too high due to experimental errors or to a deeper setting of 
the parent plants. The reason for the great increase in the Coefficient 
of variability in 1912 is harder to explain. A manure heap lay in 
the fall of 191r on one end of the row on which this selection grew 
