J. A. Harris 
453 
I. Introduction. 
Volumes have been written concerning Natural Selection — its existence or non- 
existence, its potency or its inefficiency — but much to the discredit of biologists, 
thousands of pages of this literature may be explored without finding a single 
oasis of quantitative data to relieve the monotony of the polemic desert. 
Fortunately there are a few notable exceptions, among which memoirs by 
Weldon*-]-, BumpusJ, Beeton and Pearson§, Weldon||, Di Cesnolaf, Crampton**, 
Di Cesnolaff, Kellogg and Bellj| and perhaps a few others may be mentioned 
as contributing to the direct quantitative evidence concerning the potency of 
natural selection. 
These researches, highly valuable in themselves, are only a slight beginning 
in the scientific investigation of a field of cardinal biological importance. Perhaps 
in the earlier days of Darwinism it was not possible to do much more than collect 
qualitative evidence and to reason from analogy ; one great value of the researches 
just cited is that the}'^ show that the exceedingly complex problems of natural 
selection can be made the field of quantitative investigation, and now that this 
fact has been demonstrated I think that we should stigmatize as merely pseudo- 
scientific discussions of selection not based on quantitative data. 
Some years ago it occurred to me that it might be possible to ascertain some 
facts concerning selective elimination by comparing the characters of ovaries which 
develop into mature fruits with those which do not. That this is a distinct 
problem from that of the selective elimination of individuals I am quite aware. 
It is a consideration of the fitness of certain (morphological) types of organs 
* Weldon, W. F. R. : "An attempt to measure the death-rate due to the selective elimination of 
Carcinus moenas with respect to a particular dimension." Proc. Roy. Soc. Lond. Vol. lvii. pp. 360—379, 
1895. 
t Weldon, W. F. R. : Presidential address, Zoological Section. Trans. Brit. Assoc. Bristol, 1898, 
pp. 887—902. 
X Bumpus, H. C. : " The elimination of the unfit as illustrated by the introduced sparrow. Passer 
domesticus." Biol. Led. Del. Mar. Biol. Lab. Wood's Holl, 1897—98, pp. 209—226, 1899. 
§ Beeton, Mary, and K. Pearson : " Data for the problem of evolution in man. II. A first study of 
the inheritance of longevity, and the selective death-rate in man. " Proc. Roy. Soc. Vol. lxv. pp. 290 — 305, 
1899. 
II Weldon, W. F. R. : "A first study of natural selection in Clansilia laminata." Biometrika, 
Vol. I. pp. 109—124, 1901. 
H Di Cesnola, A. P.: "Preliminary note on the protective value of colour in Mantis religiosa." 
Biometrika, Vol. m. pp. 58, 59, 1903. 
** Crampton, H. E.: "Experimental and statistical studies upon Lepidoptera. I. Variation and 
elimination in Philosamia cynthia." Biometrika, Vol. iii. pp. 113—130, 1904. See also Jotirn. Exp. 
Zool. Vol. II. pp. 425—430, 1905. 
ft Di Cesnola, A. P. : "A first study of natural selection in Helix arbustorum." Biometrika, Vol. v. 
pp. 387—399, 1907. 
Kellogg, V. L. and Ruby G. Bell: "Studies of variation in insects." Proc. Wash. Acad. Sci. 
Vol. VI. pp. 324—329, 1905. 
Biometrika vii 58 
