THE BEGINNINGS OF LIFE. 307 



points towards a similar probability in the case of 

 organisms. There is, however, an obvious and fun- 

 damental difference between crystals and organisms, 

 which has had an immense and quite natural influence 

 in affecting the opinions entertained as to the mode 

 of origin of each. Crystals do not undergo a process 

 of c spontaneous division,' and reproduction is unknown 

 amongst them. How else could they arise, then, save 

 by a 'spontaneous' collocation of their atoms ? With 

 organisms and with living matter, however, the case is 

 wholly different. These are dynamical aggregates, and 

 the possession of a property of reproduction is their 

 fundamental characteristic. All the higher forms with 

 which we are most familiar do undoubtedly derive their 

 origin from organisms similar to themselves. Why 

 then should the processes with which we are so familiar 

 in the many not be applicable to all ? Why should we 

 not implicitly believe that the phrase omne vivum ex 

 vivo gives accurate expression to the law of nature ? 

 An analogical argument of so striking a nature could 

 not fail to arrest and enchain the attention of those 

 who, for other reasons, might believe or wish that the 

 dogma were true notwithstanding the fact that another 

 analogical argument speaks almost as strongly in favour 

 of the possibility of the de novo origination of some 

 organisms as specks of living matter. 



General beliefs will, then, be brought to bear upon 

 the subject, and the views entertained upon this pro- 

 blem, as to the mode of origin of some organisms, 



X 2 



