212 
E. M. EAST 
Recently Goodspeed and Clausen have published in this Journal 
(2: 332-374. 191 5) an immense amount of data on the influence 
that certain environmental factors have on flower size in Nicotiana. 
The conclusions they draw are eight in number based upon 25,000 
measurements of the length and spread of the corollas of Nicotiana 
tahacum var. macrophylla and three hybrids between N. tahacum 
varieties and iV. sylvestris, and run somewhat as follows: 
1 . Both length and spread of corolla decrease during the flowering 
season to such an extent that at the end of six weeks the average 
spread may drop 6 mm. and the average length 4.5 mm. 
2. The Fi N. tahacum X N. sylvestris hybrids are shoit-lived 
perennials, and the flowers of the second season are of approximately 
the same size as those of the first season. 
3. Removal of open flowers during the normal flowering season 
prevents nearly all decrease in size. 
4. Flowers apparently fully opened are smaller before than they 
are after anthesis, even though the anthers are partially sterile. 
5. Flowers on pot-grown cuttings are smaller than those borne on 
the field plants from which they were taken. 
6. Under favorable and unfavorable greenhouse conditions, flower 
size varies distinctly and in the same direction as the vegetative 
characters. 
7. Length of corolla is more stable than spread of corolla under 
environmental stimuli. 
8. "The only true distribution representing the flower size of a 
population must be based upon measurements which, for each plant, 
extend over the greater part of the period of flowering normal for the 
given species or hybrid group, or cover an identical portion of the 
flowering period of each plant." 
The data were collected and these conclusions drawn, the authors 
say, "to establish tentative criteria in keeping with which flower 
size investigations, in Nicotiana at least, should be carried on and 
interpreted." 
The statements of Goodspeed and Clausen and those quoted from 
my own paper seem at first sight to be irreconcilable. Indeed, the 
authors have done me the honor of devoting a considerable portion 
of their paper to criticizing my views and methods. For example, 
because it was maintained that flowers are constant under different 
environments compared with the changes exhibited by vegetative 
