Amongst  the  culture  yeasts  separated  from  such  a  mix-
ture, several  species  may  often  be  found  which  are  of  use  in

*  The  flasks  and  apparatus  which  are  used  in  my  laboratory  can  be  obtained
from  F.  C.  Jacob,  Hauserplads  14,  Copenhagen,  and  from  Dr.  Rohrbeck.
Karlstrasse  24,  Berlin.
