1 14 specific Genesis 



finished bodies, but in the properties of the surrounding media, por- 

 tions of whose constituents are changed into crystals, according to 

 these properties and to other conditioning circumstances.' 



If this is so, then when a broken crystal completes itself, 

 the determining forces reside exclusively in the media, and 

 not at all in the crystal with its broken surface ! The first 

 atoms of a crystal deposited arrange themselves entirely 

 according to the forces of the surrounding media, and their 

 o^vn properties are utterly without influence or effect in the 

 result ! 



To my mind, I confess, it would appear manifest that 

 those marvellously delicate and complex ice mosses, which in 

 the winter season occasionally fringe our walls and palings, 

 are not due to forces residing in the atmosphere only, but 

 also in the crystalline particles already deposited and in 

 course of deposition. 



Professor Tyndall's teaching differs widely from that of 

 Mr. Chauncey Wright. Speaking of the formation of pyra- 

 midal crystals of salt, he says : — 



' The scientific idea is that the molecules act upon each otlwi\ . . . 

 that they attract each other and repel each other at certain definite 

 points or poles, and in certain definite directions, and that the pyra- 

 midal form is the result of this play of attraction and repulsion.' ^ 



Mr. Wright seeks to refute the parallelism asserted by Mr. 

 Murphy and by me to exist between crystals and organisms, 

 saying :— 



*In organisms, no doubt, and as we may be readily convinced 

 without resort to analogy, there is a great deal that is really innate,, 

 or dependent on actions in the organism, which diversities of external 

 conditions modify very little, or affect at least in a very indeterminate 

 manner, so far as observation has yet ascertained.' 



Here Mr. Murphy and I are fortunately at liberty to 



1 Essays on the Use and Limit of the Imagination in Science, 2nd edition,, 

 1871, p. 57. 



