MU. W. A. NICHOLSON ON RANUNCULUS FICARIA. 
379 
XVII. 
VARIATIONS IN RANUNCULUS FICARIA , WITH 
SOME STATISTICS. 
By W. A. Nicholson, Huh. Sec. 
Read 25th February , 1202. 
The subject of the variations of our common wild plants and 
animals is one fraught with special interest, not only for the field 
naturalist, but, as has been shown by some recent work, for the 
mathematician. I allude here, more particularly, to the writings of 
Professor Karl Pearson, F.R.S., who has treated variation and 
vital Statistics from the mathematical point of view. In his 
‘Grammar of Science,’ 2nd ed. p. 374, he says: “Biologists, even 
as physicists have done, must throw aside merely verbal descriptions 
and seek in future quantitative precision for their ideas.” M r. Galton, 
Professor Weldon, and others, have also applied statistical methods 
to biology. 
Figures and statistics may seem out of place in the transactions 
of a Naturalists’ Society ; but if they assist us in forming a truer 
idea of any fact in nature, we must not neglect them, however 
unattractive, at first sight, they may appear. 
From Professor Pearson’s point of view, in considering variations 
in biology, the important point is to measure the amount of 
variation, either by actual counting, or in other cases by exact 
measurements, of a large number of specimens. The average or 
mean is calculated, and, by a method frequently used in Statistics, 
the Standard Deviation, or amount of variation from the mean, is 
then worked out. The Standard Deviation affords a test of the 
amount of variation which any particular species is undergoing. 
I am not going into Professor Pearson’s further applications of 
his methods, but would refer any one specially interested in this 
