FACTORS INFLUENCING FLOWER SIZE IN NICOTIANA 333 
rather greater degree of fluctuating variability under similar conditions 
attending development. Thus we read that, ''During the past four 
years I have grown about 20 species of Nicotiana in considerable 
numbers. They have been grown under very diverse conditions. 
Some have been starved in four-inch pots, others have had the best of 
greenhouse treatment; some have had poor field conditions, others 
have had all field conditions practically at their best. The height of 
the plants, the size of the leaves, and similar size complexes have 
varied enormously, but the size of the corollas has varied scarcely at 
all. For example, plants of N. sylvestris Speg. & Comes grown to 
maturity in four-inch pots produced no leaves longer than 7 inches. 
On the other hand sister plants of the same pure line produced leaves 
30 inches long in the field. Both series, however, produced flowers 
with the same length and spread of corolla. Furthermore, cuttings 
from 20 of the field plants reported in this study were rooted and grown 
in small pots in the greenhouse. Their blossoms were the same size 
as those of the field plants from which they came." The data herein 
to be listed seem, in our opinion, to demonstrate that in the Nicotiana 
cultures grown in the University of California Botanical Garden a 
rather different condition of affairs prevails so far as the ''character 
complex," corolla size, is concerned. East also finds (ibid., p. 181) 
that in general " corolla spread is . . . correlated with corolla length." 
As a broad generalization this statement is undoubtedly correct. On 
the other hand, the fact that in our experience corolla length and corolla 
spread behave in a different manner with reference to their stability 
under "the conditions attending development," suggests that the 
assumption of a too definite correlation when attempting to interpret 
the results of studies of flower size inheritance in Nicotiana must be 
very guardedly indulged in. The fact that in our experience corolla 
size does vary distinctly under some of the most normal and inherent 
conditions attending development and that corolla spread and corolla 
length do not respond alike in this respect has in a great measure 
been the cause of the difficulties in technique and interpretation 
above mentioned. 
The data presented in this report were collected in connection with 
a number of separate and distinct experiments, and pertinent data 
upon an almost equal number of plants were also available. It is the 
purpose of the present report -to illustrate by the presentation of the 
results, actually accumulated in the field, the effects of various en- 
