The writer has repeatedly tried to scrape off bacteria from the sur- 

 face of freshly fermented Florida tobacco leaves, but has searched in 

 vain with the highest magnifying power for the millions of microbes 

 natnrallj^ to be expected if they really play a part in raising tlie tem- 

 perature of the fermenting heap and bringing on powerful chemical 

 changes. These ferment inr/ leaves are, however, exceedingly smooth 

 and clean, and the scrapings obtained from them consist almost exclu- 

 sively of particles of the epidermis. Only here and there, by applica- 

 tion of staining methods, some small globules become visible which 

 might represent spores or cocci. Certainly so few microbes could never 

 be held responsible for the action in the fermenting heap, but, on the 

 contrary, colonies of luxuriant growth, as seen spreading i)rofusely 

 upon potatoes or agar, ought to be expected. It is very instrtictive 

 that Behrens in his attempt to isolate bacteria from the surface of 

 cured tobacco leaves, obtained two spore-forming microbes, Bacillus 

 suhtilis and a Clostridium. One can not suppress the supposition that 

 both kinds have been present only as spores and as such would remain 

 inactive during the so-called fermentation i^rocess, as there is not 

 sufficient water to bring on their germination. 



It is evident that for the proper examination of fermenting tobacco 

 leaves one must avoid petuned leaves, upon which all kinds of microbes 

 can be found when a putrefying i^etuning liquid is applied. But this 

 liquid is not at all essential for starting the fermentation process. The 

 fermenting Florida tobacco leaves the writer had under examination 

 were not petuned, and he most emphaticall}^ declares (1) that there are 

 no bacteria in the cells of the tobacco leaf, and (2) that the surface is 

 remarkably clean and is not covered by a bacterial coating. This 

 observation was made also by Mr. Albert F. Woods, of the Division of 

 Vegetable Physiology and Pathology, two years ago in his studj' of 

 si)ots on fermented leaves. 



The chief object and pride of the tobacco manufacturer is to i^roduce 

 a cigar leaf of faultless quality. This would be impossible were bac- 

 teria to develop their activity i^romiscuously on the surface, as their 

 first step would be to reach the nourishing material in the interior of 

 the cells, otherwise they would be incapable of multiplying except for a 

 short time. In gaining entrance to the cells the cellulose walls would 

 have to yield, or. in other words, the surface of the leaves would be 

 attacked. 



We have here quite a different case from that of the fermentation of 

 sauerkraut, which contains over 92 per cent of water and a proportion 

 of cellulose to water as 1 to 02. In the fermenting tobacco leaf the 

 amount of water is generally below 25 per cent and the i)roportion of 

 cellulose to water is generally less than 1 to 1.5. In fact, the water 

 present merely suffices to impregnate the cellulose walls and contents 

 of the cells, and is entirely insufficient to bring organic matter from the 

 interior of the cells to the surface, where bacteria might feed upon it. 



