Variation of the number of sepals in Ane^none nemorosa. 
By G. UDNY yule. 
[Received January 9, 1902.] 
It is a question of some interest how far local races of plants vary from year to year. An 
abnormal characteristic, or a larger proportion of abnormal individuals, may be exhibited at 
some one time by one local race ns compared with another, but unless the same race be re- 
observed, it cannot be certain that the abnormality is not merely a temporary condition, due 
to an unusually wet or dry season, or to the fact that the different races compared were 
observed at different times in the season. With individuals so largely subject to external 
influences as plants a good deal of caution must be used in drawing conclusions. 
In the spring of 1898, between the 20th and 23rd of April, I counted the number of sepals 
on three different series of Anemone nemorosa in the neighbourhood of Bookham, Surrey. The 
three places from which they were taken are within a mile or two of each other, and on the 
same clay subsoil. A was a copse by Banks Common, Etfingliam ; the underwood had been 
recently cut, so the place was fairly exposed, there being few large trees. B was a spot in 
one of the Eastwick woods ; the underwood had not been cut for a long time, so it was close 
growing and the ground very sheltered. C was a narrow strip of copse, only a few yards wide, 
between two fields in the parish of Little Bookham. It sloped slightly down a hill. The 
underwood was low, about a year old, so the situation may be called exiiosed. The sepals were 
counted on the spot, a thousand being taken in each place. The flower is a delicate one, 
and it is necessary to take a good deal of care not to count specimens that have lost one or 
more sepals ; I never admitted a flower that dropped a sepal on being shaken or blown. The 
frequencies are given in the first three columns of Table I. B exhibits the largest pi-oportion 
of sixes and the least variability, C the lowest proportion of sixes and the greatest ^-ariability, 
A is intermediate. 
A fortnight later the strip of copse C was revisited. It was late in the season, the anemones 
were half over and the 500 which were counted nearly cleared the strip. The frequencies per 
1000 are given in Column 4. It will be seen that the distribution is quite different to that of 
Column 3 ; flowers with five and six sepals are more frequent, with seven or more sepals less 
frequent, than earlier in the season. The S.D. is however sensibly the same, being in both 
cases markedly higher for C than for either A or B. The intervening fortnight had been wet. 
In the spring of 1899 the two places A and C were again visited and 500 flowers counted at 
each ; it will be noted that the visit was made nearly a fortniglit earlier tlian in the preceding 
year. The frequencies per 1000 are given in Columns 5 and 6. The distribution for A resembles 
31—2 
