148 INTRODUCTION TO SCIENCE 



certainly been extraordinarily ingenious in evad- 

 ing the old criticism of crude views that the in- 

 >nuated immaterial factor, if it is to be effective, 

 must invalidate physico-chemical laws. 



As an appendix to this brief discussion, we 

 wish to refer to the very strongly expressed con- 

 clusions of the most distinguished physicist of the 

 age Lord Kelvin. He was, indeed, no biologist, 

 but the opinions held by one of his intellectual 

 eminence claim our attention. He knew how far 

 his Physics could go. 



"The only contribution of dynamics to theo- 

 retical biology is absolute negation of automatic 

 commencement or automatic maintenance of life." 



"The opening of a bud, the growth of a leaf, 

 the astonishing development of beauty in a flower, 

 involve physical operations which completed 

 chemical science would leave as far beyond our 

 comprehension as the differences between lead 

 and iron, between water and carbonic acid, be- 

 tween gravitation and magnetism, are at present. 

 A tree contains more mystery of creative power 

 than the sun, from which all its mechanical energy 

 is borrowed. An earth without life, a sun, and 

 countless stars, contain less wonder than that 

 grain of mignonette." 



AN ILLUSTRATION. Let us select some instance 

 of animal behaviour and look at it from the 

 mechanist and vitalist point of view. We take a 



