Origin and Primal Condition of Man. 



49 



patible with any form of life whatever. To begin then at 

 the beginning we must inquire into the possibility of sponta- 

 neous generation. Did it ever occur ? Does it occur still ? 

 The general maxim is omne vivum a vivo, and so far as in- 

 vestigation has yet conducted us this is the universal rule 

 of nature. But spontaneous generation, if it exist at all, is 

 only in the case of the lowest and minutest forms of life, 

 mere monads and protoplasms, the spontaneous generation 

 o£ which may forever elude our observation, as it cer- 

 tainly has thus far done. We can render no verdict on 

 spontaneous generation but that of not proved ; but this 

 is by no means identical with " disproved." We can say 

 only that for aught we know life may in its simplest forms 

 thus originate, or it may not ; but that the only method 

 whereby we know life to originate is from a living being. 

 Mivart inclines to believe in spontaneous generation, as it 

 would seem from his quoting without dissent the view of 

 Bastian that matter exists in two conditions, the crystal- 

 line (or statical) and the colloidal (or dynamical) and that 

 from matter in the latter condition, organic life may be 

 developed (Mivart, p. 283 ; also 247). There are scientists 

 who believe the work of creation to be now complete, how- 

 ever, for the reason that no new species of plant or animal 

 has ever been shown to arise in the course of scientific re- 

 search. Wallace has pointed out (see Nature, March 3, 

 1870, p. 457), that the last 60,000 years having been excep- 

 tionally unchanging as regards eccentricity of the earth's 

 orbit, evolution of species may have been exceptionally 

 rare. But here again, it is plain, that mere ignorance is 

 not disproof. When observation fails, we must fall back 

 on analogy, and, until proof can be obtained, endeavor as 

 far as possible to supply the lack of certainty by reasona- 

 ble probability. Among higher animals, life originates 

 only from two parents of different sexes ; while among some 

 [Trans. vii.~\ 7 



