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CHAPTER IV. 



The Growth of Different Organis.ms in a State of 

 Purity : Their Autonomy* 



Our observations in the preceding chapter will have shown 

 that organic liquids, natural or artificial — the wort of beer 

 amongst others — if exposed to contact with the air, rapidly 

 develop various forms of life. This is a natural consequence 

 of the mode of impregnation. The fertility of the liquid 

 depends on the various microscopic germs which are deposited 



* In the course of this work we shall combat, by means of experi- 

 mental proofs which appear to us irrefragable, the opinions which many 

 writers entertain on the subject of certain transformations of organisms 

 — that of peniciUium gJnuciim into ferment, or mycoderma ; of bacteria 

 into lactic ferment ; of ferment into vibrios ; of mycoderma aceti into fer- 

 ment, and so on. Nevertheless, we shall pronounce no a priori opinion 

 on the question whether the inferior organisms, which will be the subject 

 of this chapter, and which include yeast and the fei-ments properly so 

 called, are perfect beings in their habitual form, or whether they are 

 susceptible of polymorphism. It is with this reservation that we employ 

 the word autonomy. If we claim polymorphism for any species, we shall 

 not do so without furnishing proofs. Some organs detached from higher 

 organisms, and some beings in a certain phase of their existence, may 

 reproduce themselves iinder a special form, with special j^roperties, when 

 brought into media and under conditions that are unfit for the production 

 of the plant or animal under its other shape or ordinary mode of repro- 

 duction. Modern Science affords many examples of this, and certain 

 alcoholic ferments present us with analogous facts ; but to wish to stretch 

 these facts beyond their due significance, and to admit a polymorphism 

 that cannot bo proved, in consequence of a belief that it is possible, or 

 on the faith of confused observations, is to indulge in gratuitous assertion 

 from a mere spirit of system. 



