Mr Lawrence Balls, Pre-Determination of Fluctuation. 469 
_ Pre-Determination of Fluctuation. (Preliminary Note.) By 
W. Lawrence Batts, M.A., St John’s College. 
[Read 4 May 1914.] 
__ A. A simple example of this phenomenon is provided by 
fluctuations in the length and wall-thickness of the unicellular 
‘epidermal hairs which coat the seed of the cotton plant, forming 
the commercial “lint.” 
Cytology shows that the elongation of the lint-hair is com- 
pleted within the first 25 days from the opening of the flower, 
after which the thickening of the cell-wall begins. It might be 
expected that length would be mainly determined by environ- 
‘mental conditions acting round about the 16th day of maturation 
of the capsule, and thickness by conditions round about the 40th 
day, the capsule opening on the 50th day. 
Statistical examination of lint ripened from flowers opening 
on sixty successive days, with determinations of thickness made 
‘in the form of Breaking-strains of single fibres, gives fluctuation 
curves showing rapid changes of considerable magnitude. 
The correlation between length and strength in one set of 
samples was — 0°42. If the curves are shifted “21 days, so as to 
bring them into relative positions which the cytological evidence 
has indicated (40 — 16 = 24 circa), they are seen to be very closely 
‘similar, and the value of “r” turns over to + 0°60. 
‘Thus the length of lint in capsules which were going to open on 
‘Sept. 21st could be foretold by determining the strength of those 
capsules which were already open on Sept. Ist. 
Subsequent events cannot affect the pre-determined length, 
‘though the subsequent thickening may be of any degree. 
B. Flowering is a dhonachon which fluctuates enormously, 
‘and is not usually regarded as a “character” at all. There are 
nevertheless definite differences between species and varieties in 
this-respect, largely dependent on the branching habit. 
From a large series of statistical records of the flowering day 
by day in plots of Egyptian cotton, assisted lately by comparison 
with similar records taken by other workers using the writer’s 
-methods*, it has become clear that daily fluctuations in the 
‘number of flowers opening on the Mean Plant are inde- 
‘pendent of the site (over several square miles)+, the water- 
‘supply, age of the plant, space allowed per plant, and the 
variety grown. 
* Egyptian Government Survey Department Papers, 24 and 31. 
+ Since communicating this note I have found the fluctuations to be simul- 
taneous in sites separated by 170 kilometres; the plants of all Egypt all attempt 
to behave alike. 
VOL. XVH. PT. VI. 31 
