Stout & Boas: STATISTICAL STUDIES IN CICHORIUM 357 
tinuous. The further important conclusion was reached that such 
discontinuous specific differentiation arises through processes 
operating in the development of the individual and these processes 
were assumed to involve rhythmic cell divisions. It was also 
suggested that there is a relation between flower number and 
phyllotaxy. 
It was early recognized, however, that the maxima for species 
do not all fall in a well-defined series and hence attempts were 
made to show that in such cases other series were represented. 
From the first, it was evident that there was often a wide range of 
variation in flower number in a species, but the view was taken 
that the variations within a species or a race were solely due to 
chance, and that the facts could be accurately determined by 
Galtonian treatment of populations. 
The more recent work has been very generally directed to the 
study of variation within a species. Processes operating within 
the population have received attention. Studies have become 
more particular and individual in scope. Various hitherto unre- 
vealed sources of variability, intraseasonal, interseasonal, environ- 
mental, racial, individual, and partial were thus demonstrated. 
To the present time, however, these studies have been largely 
dominated by the view that the variations are those of chance. 
The demonstration in a few cases that such variations, especially 
partial, are not purely due to chance, but may proceed in a dis- 
coverable manner, has revealed a source of possible error in much 
of the work done and emphasizes the desirability of combining 
extensive studies with a study of the organization of individuals 
as units. 
It seems clear that intensive studies of individual and partial 
variabilities should serve as a basis for extensive study of species 
as such. Through such methods we may hope more adequately 
to determine the facts which serve as a basis of judgment regarding 
the processes operating in ontogeny, phylogeny, and evolution. 
THE PROBLEMS IN CICHORIUM INTYBUS 
The statistical studies here reported for Cichorium Intybus 
were begun with the aim of determining the facts as to partial and 
individual variability for such a character as the total number of 
