( 409 ) 
positive and the variability-coefficient of the well-fed plants greater 
than of the badly-fed ones, whereas in the other characters the 
sensibility-coefficient is negative and the variability-coefficient greatest 
in the badly-fed plants. 
Even with the same species one character shows a greater, another 
a smaller variability when the cultures grown under favourable and 
unfavourable nutritive conditions are compared. With /berzs amara 
the length of the plants from the fertile earth is more variable than 
that of the plants from the sandy soil, other characters, on the other 
hand, show greater variability in the badly-fed culture. In the same 
way in Anethum graveolens the variability is greatest with the num- 
ber of lobes of the well-fed plants and with the number of flowers 
and umbel-rays of the badly-fed ones, while with Malra vulgaris 
the length of the leaf-stalk and the number of akenes of the well-fed 
plants, but, on the other hand, the length of the blade of the plants 
from the sand, show the greatest variability. 
Summarising the results obtained, we see that nutrition influences 
the median value and the variability of the characters. Besides it 
appears that the sensibility-coefficient of the median is very different: 
1. for different species compared among each other. 
2. for different characters of the same species. 
And about the variability we saw: 
Q 
1. that with good nutrition the variability-coefficient is fairly 
constant for different characters of the same species, but very diver- 
gent for the different species. 
2. that with bad nutrition two of the species studied show great 
differences between the variability-coefficients of the different charac- 
ters of the same species, while with one species the variability- 
coefficients of the various characters diverge relatively little. 
Q 
F En BEI malas ee 5 . Ayo 
3. that the sensibility-coefficient of — diverges greatly for different 
species and characters and varies between —1,40 and —+ 0,29. 
: ese ve ORL, 
4. that for some characters the sensibility-coeffieient of us 
positive and good nutrition results in an increase of the variability: 
while for other characters, even of the same species, this coefficient 
is negative. 
In what precedes, there has only been question of those charac- 
ters which show symmetrical or sensibly symmetrical curves and 
Which, when expressed in constants, yielded the results mentioned. 
From these the curve of the number of branches of the third 
