Stout & Boas: STATISTICAL STUDIES IN CICHORIUM 335 
4. Individual variations from the usual performance as to seasonal 
Пертейде усуе. Т Сау IC a Ea eee) Se Se ы. 410 
5. Variation іп partial variability with the age of a plant.......... 412 
in range and distribution of modal numbers. ......... 9 
IV Сызды of flower number in the variety red-leaved Treviso... 421 
V. Characteristics of flower number in a hybrid generation of a cross 
between plants of red-leaved Treviso and a wild plant (A)....... 427 
VI. Selection and heredity; characteristics of different progenies and 
various lines of descent derived from a cross between a wild 
plant (A) and plants of the variety Barbe de Capuc e AD ы.) 
. General comparison of progeny with immediate oni as to 
КӨЛІНЕН аме i ee ee ke ee new. s Sate V 428 
2. Detailed analysis of six races as to inheritance of flower number 
per hende. полис aD RO E Ut UA le acuta x А mph ac a ON S 432 
A A Gemi-dwart face (race 1) 21. пра ШУ eere RR E 432 
P A dwart Pace (асе 2) LY AI т, ұлы ГЕ ОЛООР Stare qe 435 
C. Race with intermittent growth (race 3) зоната вал. 436 
D. A brittle-stemmed race (race 4) .........-./....5....-.-- 437 
E. А semi-dwart bushy race (сасе 5)... os es Rr Ir 439 
А tall-srowing race (race б) а eee ee рез 441 
DISCUSSION AND CONCBUSIONUC ара IUS Ley eie En ed arae rte 446 
ЕРОС АЕН 5 миына Ms ае А thus d eo E RR SU FE Mrs е Se 454 
PX AME TIONS OR PLATAGA сық ата uU Le Lr sh Сы ақыт» 
INTRODUCTION 
Much study and speculation haye been directed to the so- 
called fluctuating variations in the effort to determine their sig- 
nificance in development, in heredity, and in evolution. One of 
the principal reasons why such investigations have not been more 
conclusive undoubtedly rests in the difficulty of properly grading 
each of the individuals that comprise the species, the population, 
the generations, or the lines of descent to be analyzed. 
This difficulty is frequently present in the more readily n meas- 
urable or quantitative characters, especially when the estimate 
of the individual involves measurements of homologous organs 
among which there is also fluctuating variability. There are in 
such cases two grades of fluctuating variability: one is an individual 
variability (using this term as defined by de Vries, от, p. 37, to 
refer to differences between individuals as such), the other is a 
partial variability (de Vries, 'or, p. 37) which is a variability 
within the individual. The latter exists within the former and 
when present the estimate of the individual and of individual 
variability involves partial variability and is only adequate to 
the degree that the determination of partial variability is adequate. 
