THE AMERICAN BOTANIST 3 



of ginger and a couple of granules of the ginger beer plant, 

 the whole being left to stand uncovered. The liquid soon be- 

 gins to ferment very briskly, is bottled at the end of twenty- 

 four hours and consumed within the next two days. The so- 

 called ginger beer plant, was studied by H. M. Ward ( Philo- 

 sophical Transactions 1892: 125 with 6 plates; Proc. of the 

 Royal Soc. 1892.) It consists of whitish or brownish trans- 

 lucent lumps and is the mixture of a yeast (Saccharoinyces 

 pvriformis) and a fission fungus (Bacterium vermiforme.) 

 The cell walls of the latter become gelatinized, the sheath be- 

 ing frequently ten times greater than the diameter of the cell. 

 It stands in symbiotic relations with the Saccharoinyces pyri- 

 fonnis, so that the development of one is facilitated by the 

 presence of the other. The lumps of the plant are kept in a 

 state of saltatory motion by the liberated carbon dioxide. 

 The chief products of the fermentation are carbon dioxide, 

 lactic acid, alcohol and acetic acid. You will find a short 

 reference to it in my book on page 140, also in Garden and 

 Forest VI. 50." 



It will be seen from the foregoing, that vinegar bees are 

 essentially like lichens, in that two different plants have 

 formed a partnership that is mutually helpful. In the making 

 of ordinary vinegar, both yeast and bacteria are necessary. 

 The yeast splits the sugars and starches into carbon dioxide 

 and alcohol and the bacteria finish the job by splitting alcohol 

 into acetic acid, that is, the sour of vinegar. In the vinegar 

 bee plant or. partnership, the work of splitting sugar and al- 

 cohol, can procede side by side and thus the rapid production 

 of vinegar is accounted for. 



The vinegar produced is to all appearances good vinegar, 

 though it lacks some of the bouquet possessed by vinegars 

 made from fruit juices, owing to the lack of the essential oils 

 which they contain. The bee vinegar is not quite as strong 

 as other vinegar owing to the small amount of sugar, the 



