22 THE DATA OF BIOLOGY. 



talloids of high molecular mobility or diffusive power, that 

 are capable of decomposing these complex colloids, or of 

 facilitating decompositions otherwise caused; and from these 

 complex colloids, when decomposed, there result other crys- 

 talloids (the two chief ones extremely simple and mobile, and 

 the rest comparatively so) which diffuse away as rapidly as 

 they are formed. 



And now we may clearly see the necessity for that pecu- 

 liar composition which we find in organic matter. On the 

 one hand, were it not for the extreme molecular mobility 

 possessed by three out of the four of its chief elements; and 

 were it not for the consequently high molecular mobility of 

 their simpler compounds ; there could not be this quick escape 

 of the waste products of organic action; and there could not 

 be that continuously active change of matter which vitality 

 implies. On the other hand, were it not for the union of 

 these extremely mobile elements into immensely complex 

 compounds, having relatively vast molecules which are made 

 comparatively immobile by their inertia, there could not 

 result that mechanical fixity which prevents the components 

 of living tissue from diffusing away along with the effete 

 matters produced by decomposition. 



§ 8a. Let us not omit here to note the ways in which the 

 genesis of these traits distinguishing organic matter con- 

 forms to the laws of evolution as expressed in its general 

 formula. 



In pursuance of the belief now widely entertained by 

 chemists that the so-called elements are not elements, but are 

 composed of simpler matters and probably of one ultimate 

 form of matter (for which the name " protyle " has been sug- 

 gested by Sir W. Crookes), it is to be concluded that the for- 

 mation of the elements, in common with the formation of all 

 those compounds of them which Nature presents, took place 

 in the course of Cosmic Evolution. Various reasons for this 

 inference the reader will find set forth in the Addenda to an 



