Stout & Boas: STATISTICAL STUDIES IN CICHORIUM 339 
is at ІЗ and the range from ІІ to 23; for the 250 counts the 
maximum is 13 and the range from 10 to 23. Ludwig thus 
failed to find any evidence that here differences in flower number 
may appear according to age of a plant or to different stages in 
the period of bloom, such as will be reported in this paper for 
Cichorium. 
For Anthemis arvensis Ludwig (705) reports that for 1,802 
flower heads the number of ray-flowers ranged from 2 to 21 with a 
maximum at 8 and some indications of a secondary one at 12-13. 
In only two cases did Ludwig ('87) make a study of individual 
plants. In Achillea Ptarmica the modes for number of ray- 
flowers were determined for each of 79 plants; 30 plants gave a 
mode at 8; for 17 the mode was at 13; and for the other 32 the 
modes were about evenly distributed at numbers ranging from 
9 to I2 inclusive. The total number of flower heads counted was 
1,048 and the number of ray-flowers ranged from 6 to 15, with a 
maximum at 8. For Senecio Jacobaea the distribution of ray- 
flower number for 5 individual plants was studied. The range 
here was small, being from 12 to 14 and the total number of heads 
counted was 109. 
In only a few cases does Ludwig consider the number of all the 
flowers produced per head. Such a study for Bellis perennis has 
been noted above. For Senecio nemorensis he presents ('96) data 
for ‘500 heads, which show that the total flower number рег head 
ranged from 15 to 26 with maxima at 18 and 21, and the maximum 
for the ray-flowers in 357 heads of these was 5, with a very small 
variability. In these studies, however, the behavior of individual 
plants was not considered. Studies of total flower number were 
made in Senecio Fuchsii (796), Centaurea Суапиз (96), C. Jacea 
(96), and Solidago Virgaurea (796), but the number of observa- 
tions is too small for the determination of the specific character- 
istics, which was the object of his interest and studies. 
Il. THEORIES REGARDING THE EVOLUTION AND DEVELOP- 
MENT OF FLOWER NUMBER PER 
A most important conclusion which Ludwig reaches from his 
studies is that the maxima for the number of ray-flowers and the 
total number of flowers in the Compositae and the number of rays 
