408 FRAGMENTS OF SCIENCE 



first structural effort; we have here the earliest groping 

 of the so-called *' vital force," and the manifestations of 

 this force in plants and animals, though, as already stated, 

 indefinitely more complex, are to be regarded of the same 

 mechanical quality as those concerned in the building of 

 the crystal. 



Consider the cycle of operations by which the seed 

 produces the plant, the plant the flower, the flower again 

 the seed, the causal line, returning with the fidelity of a 

 planetary orbit to its original point of departure. Who 

 or what planned this molecular rhythm? We do not 

 know — science fails even to inform us whether it was ever 

 ** planned" at all. Yonder butterfly has a spot of orange 

 on its wing: and if we look at a drawing made a century 

 ago, of one of the ancestors of that butterfly, we probably 

 find the self-same spot upon the wing. For a century the 

 molecules have described their cycles. Butterflies have 

 been begotten, have been born, and have died; still we 

 find the molecular architecture unchanged. Who or what 

 determined this persistency of recurrence? We do not 

 know; but we stand within our intellectual range when 

 we say that there is probably nothing in that wing which 

 may not yet find its Newton to prove that the principles 

 involved in its construction are qualitatively the same as 

 those brought into play in the formation of the solar sys- 

 tem. We may even take a step further, and affirm that 

 the brain of man — ^the organ of his reason — ^without which 

 he can neither think nor feel, is also an assemblage of 

 molecules, acting and reacting according to law. Here, 

 however, the methods pursued in mechanical science come 

 to an end; and if asked to deduce from the physical inter- 

 action of the brain molecules the least of the phenomena 



