THE DIRECTION OF MOTION. 241 



the early observations which led him to this generalization, 

 he formulates it thus: 



" Organic form is the result of motion." 

 " Motion takes the direction of least resistance." 

 " Therefore organic form is the result of motion in the 

 direction of least resistance." 



After an elucidation and defence of this position, Mr. 

 Hinton proceeds to interpret, in conformity with it, sun- 

 dry phenomena of development. Speaking of plants he 

 says : 



" The formation of the root furnishes a beautiful illus- 

 tration of the law of least resistance, for it grows by insinuat- 

 ing itself, cell by cell, through the interstices of the soil; it 

 is by such minute additions that it increases, winding and 

 twisting whithersoever the obstacles it meets in its path 

 determine, and growing there most, where the nutritive 

 materials are added to it most abundantly. As we look on 

 the roots of a mighty tree, it appears to us as if they had 

 forced themselves with giant violence into the solid earth. 

 But it is not so; they were led on gently, cell added to cell, 

 softly as the dews descended, and the loosened earth made 

 way. Once formed, indeed, they expand with an enormous 

 power, but the spongy condition of the growing radicles 

 utterly forbids the supposition that they are forced into the 

 earth. Is it not probable, indeed, that the enlargement of 

 the roots already formed may crack the surrounding soil, 

 and help to make the interstices into which the new rootlets 

 grow?" * * * 



" Throughout almost the whole of organic nature the 

 spiral form is more or less distinctly marked. Now, motion 

 under resistance takes a spiral direction, as may be seen by 

 the motion of a body rising or falling through water. A 

 bubble rising rapidly in water describes a spiral closely re- 

 sembling a corkscrew, and a body of moderate specific grav- 

 ity dropped into water may be seen to fall in a curved direc- 

 tion, the spiral tendency of which may be distinctly ob- 



