14 STORKS AGRICULTURAL EXPERIMENT STATION. 



A better knowledge of the actual growth of bacteria in milk 

 under normal conditions would be useful in at least three differ- 

 ent directions. 



1. The general biological laws which control living things 

 are materially concerned in such a problem. It is clear enough 

 that there must be going on in the milk, for the first day or 

 two after it has been drawn from the cow, an intense bacterio- 

 logical struggle-. The different .species of bacteria are endeav- 

 oring to adapt themselves to the conditions, and there is a 

 " struggle for existence " among them, the conclusion of which 

 is a matter of much importance in its bearing upon general 

 biological laws. 



2. The value of such a knowledge to the dairy industry 

 would doubtless be very great, although in advance it is quite 

 impossible to predict just what its practical use might be. It 

 would show what species are likely to disappear in the struggle 

 for existence. It might perhaps give us information in regard 

 to the conditions which would be required for checking the 

 growth of undesirable organisms, and favoring the growth of 

 desirable organisms. It might give practical results bearing 

 upon the problem of controlling the bacteria of the milk supply 

 as well as upon problems connected with cream ripening. The 

 lack of knowledge in regard to the real growth of bacteria in 

 milk and cream under normal conditions is doubtless one rea- 

 son why we have hitherto not been able to solve successfully 

 the problem of artificial cream ripening. 



3. The healthfulness of milk is very closely associated with 

 the problem of the growth of bacteria. It is a general belief 

 that a warm summer temperature renders milk a dangerous 

 article of food, especially for children, and that this is because 

 the warm temperature stimulates the growth of bacteria. It 

 has been consequently assumed, without any proof for the 

 assumption, that the wholesomeness of milk can be determined 

 by the number of bacteria which are present. But there are, 

 however, rapidly increasing reasons for believing that this does 

 not express the whole case. It is not simply the number of 

 bacteria in milk which is concerned in the wholesomeness of 

 the milk. Milk containing large numbers of bacteria has 

 been found to be healthful; and it is c|uite certain that milk 

 might contain onh^ small numbers of bacteria but would be 



