ANAEROBIC LIFE OF AEROBIC SPECIES 199 



was his ordinary custom, that is, that immediately 

 following their discovery, he combined them in a syn- 

 thetic experiment. If he had wished to pursue that 

 course in this case, the following undoubtedly would 

 have been his method of procedure. 



Into a series of flasks with two tubulures like those 

 we have just described, each one-third filled with steril- 

 ized must of beer, he would have introduced, by remov- 

 ing for an instant the glass stopper closing the rubber 

 tube, a small platinum wire which had been flamed and 

 passed over a spore-bearing culture of the mucor. He 

 would then have flamed the stopper and replaced it. 



Let us take for example the three Mucedinese studied 

 by Pasteur, Penicillium glaucum, Aspergillus niger, 

 and the Mucor mucedo. That makes three flasks. At 

 the end of 24 or 48 hours, the spores introduced by the 

 platinum wire will have produced a branching mycelium, 

 which if well aerated produces aerial branches sur- 

 mounted by tufts of young spores; but at the bottom 

 of these flasks, which communicate with the exterior 

 only by means of a long capillary neck, our mycelia 

 have only an insufficient quantity of air and the}^ fruit 

 little or not at all, but nevertheless in time they oxidize 

 completely the sugar on which they live. 



Before the sugar has disappeared let us connect as 

 before the straight tubulures of each of the flasks with 

 a smaller matrass which the liquid will fill up to the 

 neck, and let us pour the liquid into it. In its new 

 receptacle, this must of beer will be less exposed to air 

 than before. We might even say that it has no air at 

 all at its disposal, for the mycelium has caused all that 

 which was in the solution to disappear, and has replaced 

 it by the carbonic acid which, being given off from the 

 surface of the latter, prevents the arrival of new oxygen. 

 Under these conditions, we find that the mycelium of 



