84 FERMENTS AND MICRO -PARASITES. 



As the result of more accurate knowledge of the 

 conditions of the life and death of the lower fungi, it is 

 at the present time easy to repeat at will the same experi- 

 ments with similar results, and only he who continues 

 to hold completely false ideas as to the "biological 

 peculiarities of the micro-organisms, and who is not 

 intimately acquainted with the more recent experimental 

 methods, can at the present day ohtain results which 

 may be used in proof of the doctrine of ahiogenesis. 

 The experiments recently published by Wigand have 

 been made with complete disregard of our present 

 knowledge. Wigand starts with the view that the dis- 

 tribution of the micro-organisms, and the danger of 

 their entrance from without, is not particularly great, 

 and he does not consider it necessary to test this assump- 

 tion in the same precise manner as others have done. 



The striking result also at which many of the above- 

 mentioned observers arrived as the result of their 

 fermentation experiments, viz., that in spite of the 

 existence of putrefaction or fermentation no organisms 

 could be found in the fluids in question, rests, as we 

 can now assert with certainty, on an error. Under 

 certain circumstances it is a difficult task to recognise 

 micro-organisms perhaps degenerated and altered in 

 an albuminous fluid which has putrefied for a long time, 

 and at all events it seems essential to employ in all 

 cases the special methods which have been recently 

 .devised, such as drying, staining, &c. ; in former times 

 these methods were unknown, and as a matter of fact 

 micro-organisms were not found. But that by no means 

 justifies us in saying that in reality no organisms were 

 present at any period of the experiment ; for in more 

 recent experiments on this point they have never been 

 missed, if care was taken to examine the fluid at a 

 sufficiently early stage of putrefaction. 



2. Presence of 2. In contrast to the experiments in which putrefaction 

 found without micro-organisms, it was observed on 

 other hand that numerous micro-organisms could 

 without fer- take up their abode in fermentescible substrata, without 

 mentation. regu iti n g decomposition, fermentation, or putrefac- 



