246 BOARD OF AGRICULTURE. [Jan., 



assistants have carried on investigations in dairy bacteriology 

 in behalf of the station, especial attention being devoted to 

 the important question of cream ripening. This part of the 

 process of butter making is now known to be one of fer- 

 mentation affected by the bacteria which grow in the cream. 

 These bacteria come from various sources in the air, dairy, 

 and barn. One of the especial objects of the investigations 

 is to obtain information concerning the species of bacteria 

 that are more common in Connecticut dairies, their sources, 

 and especially their efifects upon milk and cream, and upon 

 butter made from cream which is ripened under their in- 

 fluence. The latter work includes both co-operative creamery 

 investigations and experimental inquiry in the laboratory at 

 Middletown, and has been devoted to experiments upon the 

 actual bacteriological changes which take place in the nor- 

 mal ripening of cream in ordinary dairies and creameries. 

 In these -experiments special reference has been made to the 

 changes which take place in the bacteriological contents of 

 cream during the ripening process, the purpose being to find 

 out what types or type of bacteria produce cream ripening 

 under normal conditions. Now let me read to you some- 

 thing from the report issued by the station, something which, 

 as it seems to me, is of great interest, and something new as 

 I understand it: " It is found that the bacteria which get 

 into milk during the milking are quite numerous in variety. 

 Of those which are present in milk and cream at the outset 

 there are only very few which produce lactic acid, while 

 there are large numbers of other miscellaneous bacteria. 

 During the first twelve hours or more the miscellaneous bac- 

 teria increase somewhat rapidly. The few lactic bacteria 

 which are present at the outset find the milk such a favorable 

 medium for growth that they multiply more rapidly than 

 the others, and soon surpass in numbers all the miscellaneous 

 bacteria which at first were so much more abundant. The 

 lactic bacteria continue to grow during the ripening, for 

 about 24 to 36 hours, while the miscellaneous bacteria be- 

 come less and less abundant. By the time the cream is 

 properly ripened the lactic bacteria comprise usually 98 per 

 cent, of the whole, and in many cases they seem to have 

 totally destroyed all other species. If the cream is allowed 

 to ripen for two or three days the number of these lactic bac- 



