100 A MANUAL OF BACTERIOLOGY 



to see it appear under forms of great simplicity, en- 

 dowed, like existing fungi, with the power of deter- 

 mining the formation of new protoplasm from such 

 matters as ammonium carbonates, oxalates, and 

 tartrates, alkaline and earthy phosphates, and water 

 without the aid of light. That is the expectation to 

 which analogical reasoning leads me ; but I beg you 

 to recollect that I have no right to call my opinion 

 anything but an act of philosophical faith.' 



Besides the two great theories which account for 

 the origin of life from mineral matter, 1 there are 

 others, which we now describe. It has already 

 been stated that putrefaction is the result of life, 

 not of death the result of microbian activities 2 

 but formerly many naturalists believed that by 

 putrefaction the organic elements which had com- 

 posed the body of the dead animal formed them- 

 selves by free creative power into independent 

 beings, which differed entirely from those from 

 which their material was produced, yet are in every 

 case animated, and have the power of propagation ; 

 thus the albumin and fat globules take the form of 

 microbes, perhaps also of yeasts and moulds, or even 

 of those little infusorial animals, whose presence 

 never fails in corruption. This mode of origin has 

 been called equivocal generation or generatio cequi- 

 voca. 3 Other naturalists dispute the possibility of 



1 Those of creation and spontaneous generation. 



2 The microbes being introduced from the air, water, etc. 



3 The equivocal origin of microbes must be distinguished 

 from the spontaneous generation, which we have already 

 alluded to ; for in the latter case there existed no organisms 

 on the earth. 



