612 SCIENTIFIC THOUGHT. 



is room for the statistical treatment. This treatment 

 entirely ignores the definite nature of the component 

 units, and merely investigates those properties which 

 depend upon aggregation in large numbers, the average 

 or mean results, and the chances of deviations or vari- 

 ations. Now, if organic beings are supposed to be made 

 up of immeasurably large numbers of units transmitted 

 to them by inheritance, and capable of self-multiplication, 

 they must be subject to certain regularities, to regular 

 deviations or recurrent changes ; and, under the influ- 

 ence of selection, be it artificial or automatic, to 

 certain developments which can be studied without a 

 precise knowledge of the biological, chemical, or physi- 

 cal nature of these units themselves, or of the mechan- 

 ism of their movements. Economics, meteorology, the 

 kinetic theory of gases, deal in this way with complex 

 phenomena, the exact individual history of which they 

 are quite incapable of narrating. As in the case of the 

 kinetic theory of gases we had to translate into statis- 

 tical language the phenomena of pressure, temperature, 

 volume, available or hidden energy, &c., so in dealing 

 statistically with biological phenomena, such as inherit- 

 ance, on the basis of the theory of Pangenesis, we have 

 to translate into statistical language such phenomena as 

 " types, sports of nature, stability, variation and in- 

 dividuality." " The word man," as Mr Galton says, 1 

 " when rightly understood, becomes a noun of multitude, 

 because he is composed of millions, perhaps billions, of 

 cells, each of which possesses in some sort an independ- 

 ent life, and is parent of other cells. He is a conscious 



1 'Hereditary Genius' (1892), pp. 349, 350. 



