302 THE BEGINNINGS OF LIFE. 



It is worthy of remark, however, that the germ con- 

 troversy concerning crystals can only be settled in the 

 minds of those who are content to accept the high 

 probability that the properties of any invisible portions 

 of crystalline matter would correspond with the proper- 

 ties which similar visible crystalline matter is known 

 to display. And it is this reluctance to admit an 

 equally high probability in the case of living matter, 

 which alone causes the sister controversy to continue. 

 Otherwise, the question as to the possibility of the de 

 now origination of organisms would have been amicably 

 settled long ago. 



So far as evidence derived from microscopical exami- 

 nation can be adduced, moreover, it is able to speak 

 no more decisively concerning the de novo origin of 

 crystals, than concerning the de novo origin of or- 

 ganisms. In the elucidation of this point the valuable, 

 though insufficiently known, observations of Mr. Rainey * 

 come most opportunely to our aid. In ordinary cases, 

 it is difficult to watch satisfactorily with the microscope 

 the first stage in the appearance of crystals in solutions 

 containing crystallizable matter, owing to the rapidity 

 with which their growth takes place. This is one 

 point in which crystals are strikingly different from 

 organisms. The slower growth of organisms is, how- 

 ever, as Prof. Graham pointed out, quite in accordance 

 with the general slowness of colloidal changes. But, 



1 ' On the Mode of Formation of the Shell of Animals,' &c. London, 

 1858. 



