PRINCIPLE OF LEAST ACTION 93 



believe, of a self-supporting perfectly equilibrated spherical 

 dome but that of the Pantheon at Paris. ^ A perfect 

 ellipsoidal muscle is found in placental animals for 

 expulsion of the young in which there is a perfect 

 adaptation of force to resistance." 



Dr. Haughton's three lectures on " Least Action " 

 would have furnished Paley with admirable materials ; 

 but the question is : How can chemico-physical forces 

 alone be made responsible for the Principle of Least 

 Action ? 



It is paralleled in the vegetable kingdom. Every 

 tree puts on wood sufficient to support its own weight. 

 Lianes or woody climbers of tropical countries make 

 " cables " and " girders " to resist such strains as they 

 are subjected to ; while experiments of weighting stems, 

 leaf-stalks, etc., show that such strains as are produced, 

 instantly call out the responsive powers of the plants to 

 meet them. If a bough be bent and tied back in that 

 position, it will be found after a ^q\v years to be perma- 

 nently fixed, the strain having been met and completely 

 overcome. 



From a simple experiment of tying a weight on to a 

 leaf-stalk to the formation of the skew, or ellipsoidal 

 muscle, the structures produced under strains, etc., are 

 all traceable to the responsive power of protoplasm to- 

 gether with its nucleus. 



But there is Directivity throughout, as seen by the 

 Objective Results, in the development of the tissues of the 

 skew or muscle, out of molecules of matter derived from 

 food. 



^ This was written in 1871. I am under the impression that the 

 large dome of the church at Musta in Malta, entirely built of stone, is 

 self-supporting. 



