BEER-SEED. 



167 



No bacteria were obtained on these plates. This yeast fermented grape-sugar in peptone 

 water readily and also cane-sugar and maltose, but not lactose. 



This yeast grew on potato in a thick whitish layer. It grew readily in the thermostat 



Fig. 46.* 



1 







W-K.JL ' 







\ 



\ 

 \ 



I '/ion MM 



Fig, 47.t 



'c^ r\C| 



< fiaoMM 

 Fig. 48. t 



at 28° C. On agar streaks it sporulated freely after some days, the protoplasm, rounding off 

 into two or more parts. Often three spore bodies and sometimes four or more in a cell were 

 observed (fig. 49). The appearance and behavior of this yeast sug- 

 gested Saccharoniyces cerevisiae. 



Sterile litmus milk inoculated by putting some of the grains into it 

 did not redden, did not coagulate at once and did not produce any gas- 

 bubbles. Gradually the litmus was reduced and remained reduced for 

 a very long time. The milk also finally curdled. It was blue after the 

 reduction ceased. 



It would appear, therefore, that some kefir-like grains contain a 

 yeast incapable of fermenting lactose, while grains from other sources 

 contain a yeast capable of fermenting lactose. The relation of kefir to the ginger-beer 

 fermentation remains to be determined. 



Fig. 49.; 



*FiG. 46. — Free-hand unstained section through one of the "beer-seeds," surface of grain being at left. The 

 uniform gray structure represents bacterial zoogloeae, the darker masses the undisturbed position of imprisoned clumps 

 of yeast. 



fFlG. 47. — A small portion of "beer-seed" crushed in water and drawn after staining with carbol fuchsin. The 

 yeasts buried in the zoogloeae were not budding, most of them were globose or nearly so. 



JFiG. 48. — Another crushed-out water mount of "beer-seed," showing both round and elongate yeasts, the con- 

 tents omitted, x and y stained alike with fuchsin and both forms were full of coarse granules. 



§FiG. 49. — Spores or spore-like bodies in yeasts on agar sub-culture (streak) made from an agar-plate poured from 

 crushed "beer-seed." Age 16 days. Stain, carbol fuchsin. 



