FACTORS INFLUENCING FLOWER SIZE IN NICOTIANA 365 
moist garden plot, and an almost equal number some distance away 
on higher, unshaded, and unfertilized land. Eleven of these plants 
in the early rosette stages were transplanted with soil into pots and 
grown in the greenhouse. These eleven plants were treated with 3 
applications of varying amounts of sodium nitrate, one pot receiving 
the maximum of 120 gm. and the amounts in the remaining pots 
decreasing in more or less regular ratio. Thus one pot received 3 
gm.; one, 6 gm.; one, 10 gm.; one, 15 gm.; one, 30 gm.; one, 45 gm.; 
and so on. 
No detailed measurements have been taken on the size of flowers 
on the treated plants in the greenhouse or on the plants grown under 
the contrasting field conditions. Inspection, actual comparison of 
flowers, and a few measurements, however, leave no doubt as to the 
relative size of flowers on the three groups of plants. The plants 
growing on the garden plot are in every way more vigorous and better 
developed as to vegetative characters than those on the exposed, 
unfertilized land. An off-hand inspection of the two groups of plants 
is convincing as to the fact that there is an increase in size of flowers 
more or less proportional to the increase in vegetative luxuriance. 
This fact is so very apparent that it scarcely needs the confirming 
evidence which is given by measurement and direct comparison of 
flowers from the two groups of plants. Spread of corolla is consider- 
ably larger in the flowers on the plants growing in the garden plot 
while the length of corolla is not correspondingly increased, though it, 
also, is greater. 
With reference to the treated plants in the greenhouse the smaller 
amounts of nitrate scarcely serve to increase the vegetative vigor 
over that of the central plants. An increase in size of vegetative 
characters soon occurs, however, as the amount of nitrate is increased 
and after a certain point falls until near the maximum of application 
the plants are small and weak. These latter plants produce no flowers 
or only a few flowers that are strikingly diminutive in size as compared 
with the flowers on the central plants. As the amount of sodium 
nitrate is decreased until the optimum amount for vegetative growth 
is reached, the size of flowers increases distinctly, although the flowers 
on the treated plants that show maximum vegetative vigor are only 
slightly larger than those on the control plants. Such measurements 
as have been taken confirm the above statements. The briefest 
inspection of these 11 plants has served to convince observers that 
