420 THE GRAMMAR OF SCIENCE 



critical spirit, for all three seem to me to be occasionally wanting in precise- 

 ness of definition, stringency of logic, and above all in quantitative measure- 

 ment and statistics (see my remarks, pp. 391, 416, 417, and Appendix, Notes 

 V. and vi. ). The reader may also consult an excellent little book by — 

 Thomson, J. Arthur. — The Science of Life, an Outline of the History of 

 Biology, and its Recent Advances. London, 1899. 

 Those who wish to study the quantitative theory of evolution somewhat 

 more closely may perhaps be tempted to examine the series of papers entitled 

 Mathematical Contributions to the Theory of Evolution, and Data for the 

 Problem of Evolution in Man, which since 1895 have been contributed by 

 the author and his co-workers to the Philosophical Transactions and Pro- 

 ceedings of the Royal Society (London, Dulau and Co.). Important papers 

 by Francis Galton, W. F. R. Weldon, E. Warren, and G. U. Yule from the 

 statistical standpoint will also be found in the Proceedings. 



