356 SEMI-CENTENNIAL OF TORREY BOTANICAL CLUB 
no doubt that spontaneous variations here occurred, giving in- 
creased variability, and that selection of the extremes was effective 
in giving a new race. 
X. PREVIOUS STUDY OF FLOWER NUMBER IN CICHORIUM 
INTYBUS 
It appears that the only statistical study of flower number in 
a species in which the flowers are all ligulate is that of de Helguero 
(об). 
His data were obtained from Cichorium Intybus. Не counted 
the flowers in 1,000 heads produced by 624 individuals; the counts 
were made on five different dates during August when the plants 
were approaching the end of the blooming period. “Пе piante 
furono raccolte in 5 diverse volte durante il mese di Agosto e 
percio nel periodo decrescente della fioritura." Of the total 1,000 
heads, 389 were from 389 plants which had only one head each in 
bloom at the time of collection: 300 heads were from 150 plants 
having two heads each in bloom when the counts were made: 311 
heads were from 85 plants having 3 heads open оп a single date. 
The data are treated almost solely to determine homotyposis. 
The table of correlation for the 150 pairs (two heads for each plant 
paired) gives a correlation of +0.5915. The correlation table 
for all pairing of two or more per plant gave a correlation of 
+ 0.6130. The results show that when a few heads (in most cases 
only two) are taken from a plant on a single date at the end of the 
blooming period the correlation is about +0.6. De Helguero did 
not extend his observations sufficiently to determine adequate 
values for partial and individual variabilities. 
XI. SUMMARY 
Statistical studies of such a numerical character as number of 
parts in an inflorescence were initiated about twenty five years ago 
by the very general collection of data from mixed populations. 
The method was to study species en masse. The chief aim was 
to discover specific qualities. Broad generalizations were made 
(1) that flower number is specific for species, (2) that the numbers 
characteristic of species fall in ә seriés such as that of Fibonacci, 
and (3) that evolution giving such differences has been discon- 
