134 REporT OF THE BACTERIOLOGIST OF THE 
the starter of selected bacteria so that the desired flavor might 
be always obtained. 
The problem that presents itself is not different from that which 
confronts every farmer who attempts to grow a field of oats. If 
he sows his seed upon land already filled with rapidly growin: 
clover, Canada thistles and ragweed his chances of a good oat 
crop are poor. If he first fits his land and kills off the other 
plants the oats will have a better chance. To make a success of 
this it is not necessary to kill off every weed in the field for if 
the oats are much in the majority and get the start of the others 
they will control the situation and suppress the weeds. 
The bacteria are plants of more simple form than those in the 
above illustration, but they obey the same laws of competition in 
growth. If conditions are so arranged that the starter when 
added to the cream, finds the same filled with rapidly growing 
enemies, the effect of the starter will be largely or wholly lost; 
while if it is added to cream from which all or nearly all of its 
competitors have been removed, the starter will assume control — 
of the situation and suppress its enemies. 
In the Danish machine the milk is introduced at one end of a 
cylinder surrounded by steam and flows continuously from the 
other end having been momentarily heated to the temperature 
desired. 
The temperatures used have had an upward tendency and sin: 
Dr. Bang announced that when working with tuberculous cows 
furnishing the diseased germs in their milk the milk was ren- 
dered harmless when passed through one of these machines at 
85° CO. (185° F.), this has been taken as the Danish minimum 
legal temperature for heating all the by-products that are to be 
returned to the farm for feeding purposes. 
In a country where the most determined effort is being made 
to stop the spread of tuberculosis among cattle the value of this 
protection to a dairyman who has succeeded in freeing his own 
herd from the contagion, but yet is compelled to raise his calves 
