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fluid might be able to send out fructifying branches into the sur- 

 rounding air. An extremelj* small quantity of yeast was then 

 placed in each drop of fluid, so that each drop of fluid should con- 

 tain such a number of spores only as could be readily counted, 

 and their positions reccgnised. Yeast of several kinds was 

 examined, as that from porter, beer, patent and German yeast." 

 It will suffice to give account of one kmd, that from porter 

 bottom. The granules of this were by no means uniform ; among 

 the more ordinary forms of yeast-globules there were many more 

 minute bodies, and these nearly globular ; others were much 

 curved, and of smaller diameter than ordinary yeast cells : both 

 the oblong and elliptic bodies germinated, but the former more 

 readily, and in 12 hours two additional globules had been formed 

 on one of the single bodies. Besides the more common mode of 

 germination and increase, it was observed that many of the 

 globules associated in pairs. These, and for the most part these 

 only, sent out long mucedinous filaments, which soon branched ; 

 but after the fourth or fifth day no further development took 

 place in some of the preparations. In another, however, mounted 

 in water, some were ultimately more successful. Some of the 

 threads extended into the surrounding air, acquired a flask-like 

 dilatation at their apex, and then a necklace of subglobose spores 

 exhibiting the true characters of Penicillium. 



After this account it is manifestly unfair on the part of other 

 botanists to deny, as we presently find has been done, and that on 

 the strength of mere negative results, the fact here recorded, and 

 to affirm, that no one has ever seen the mycelia of moulds originate 

 from the spores or globules of yeast. 



To follow in order of time the experiments of other botanists, 

 we find that Keess, in 1870, published at Leipzig a treatise 

 on Yeasts or Ferments. 



He states that he cultivated the spores of yeast with great care, 

 taking all precautions to exclude those of various fungi from 

 mixing themselves with the yeast-globules. He describes oval 



