370 
T. H. GOODSPEED AND R. E. CLAUSEN 
end of the previous period of flowering and of practically the same 
size as those borne at the beginning of the previous season. In other 
words, the flower size of plants the second year on their own roots, at 
the beginning of their flowering season, is the same as that of the early 
flowers produced the first year. This same fact is true of the succeeding 
year ; i. e., the third season of flowering. The rest period was, of course, 
artificially accomplished by cutting back the plants when they began to 
go out of flower and so show signs of dying back. These hybrids which 
produce no self-fertilized seed and almost no open pollinated seed show a 
striking diminution in size of flowers as the flowering season advances, 
and after a period of rest begin again to produce large flowers. As the 
second flowering season advances the size of the flowers again grows 
less. The significance of these facts in another connection has been 
commented upon elsewhere (Goodspeed, 191 3, i). 
With reference again to the relation of the inherent and normal 
conditions attending development to the size of the flower, we have 
seen that the flower itself has a period of increase in size after opening 
which is sufficiently great to be of importance. A haphazard selection 
of flowers to be measured might give a great enough preference to 
flowers not fully developed to modify the significance of the mean 
flower size determined. The same is true for flowers produced in 
different parts of the plant. It has been shown that the flowers 
produced on an inflorescence going out of flower or covered with 
developing seed capsules are smaller than those on a terminal or 
lateral inflorescence just coming into flower. 
Throughout the discussion of the tables given above, attention 
has been called to the difference between the behavior of corolla 
spread and corolla length under the influence of various conditions. 
This difference is sufficiently marked to leave little room for doubt that 
the conditions attending development do not tend to accomplish the 
same result with respect to the two types of measurement which 
together express the flower size in Nicotiana. The facts as noted 
may or may not be of any special significance as far as the general 
question of the degree of correlation between length and spread of 
corolla is concerned. As noted by East (loc. cit. p. 18) it is by no 
means uncommon to find an individual flower with a very broad 
corolla Hmb and comparatively short corolla tube"; "but one never 
finds inverse extremes in the same individual." Our results show, 
however, that there are a considerable number of individual flowers 
