304 THE BEGINNINGS OF LIFE. 



dumb-bell-like bodies will have made their appearance, 

 and with them elliptical particles of different degrees 

 of excentricity.' (p. 9.) These modified crystals are, 

 therefore, not produced more rapidly than the lowest 

 living things appear to be in other solutions during 

 hot weather. The shapes of the products in the two 

 cases, judging from Mr. Rainey's figures, are also 

 remarkably similar. (See vol. ii. Fig. 41.) 



Thus, then, the problem concerning the primordial 

 formation of crystals and of living things is essentially 

 similar in kind. Any difference in degree between our 

 present knowledge on these two subjects must not blind 

 us as to their similarity in nature. Plastide-particles 

 and Bacteria are produced as constantly in solutions of 

 colloidal matter as crystals are produced in solutions 

 containing crystallizable matter. Crystallizable sub- 

 stances are definite in composition, and give rise to de- 

 finite statical aggregations ; whilst colloidal substances, 

 much more complex and unstable, give rise on the 

 contrary to dynamical aggregations. These dynamical 

 aggregations, though they may at -first make their ap- 

 pearance in the form of plastide-particles and Bacteria, 

 are, by virtue of the properties of their constituent 

 molecules, endowed with the potentiality of undergoing 

 the most various changes in accordance with the 

 different sets of influences to which they are submitted. 

 Respecting the origin of the first visible forms which 

 appear in either kind of solution, the evidence which 

 we possess is precisely similar in nature. If such 



