520 
Mammitis, mastitis, or garget. 
This disease or series of diseases of the udder is by far the most 
frequent alteration noted. Usually only one quarter is affected, 
although the whole udder may at times be involved. The affected 
parts are greatly swollen and more or less painful in the early stages. 
The milk, at first normal in appearance, soon changes its character, 
becoming watery, light brown in color, and in some cases contains 
flocculi and pus cells, and appears tenacious, slimy, or ropy. The 
cause of this condition is usually a streptococcus, although staphylo- 
cocci are frequently incriminated in suppurative conditions of the 
udder, especially where abcess formation occurs. The milk from 
such an udder is objectionable from an esthetic standpoint and is also 
liable to give rise to gastro-intestinal disorders, especially in children. 
Such milk should be prohibited until the infiammatory condition 
entirely disappears. 
LEUCOCYTES IX MILK. 
The number of leucocytes in milk and their significance are receiv- 
ing the serious attention of those bacteriologists who are striving for 
a purer milk supply. The question as to what number of leucocytes 
should be regarded as abnormal is still the subject of investigation, 
_ but the opinions of contemporaneous workers are becoming more uni- 
form as the methods for the determination of these leucocytes are 
reaching greater perfection. Previously it was considered that but 
few leucoc*ytes were contained in the milk of healthy cows, and when 
a certain increased number of leucocytes were observed in milk it was 
suggestive of infiammation of the udder, termed mammitis or garget. 
As the milk in this disease may contain pus without changing the 
aiipearance of the product, such milk may readily be accepted by the 
consumer as normal. It is therefore of importance to be able to 
designate the cows and the milk so affected, especially as the causative 
agents of this condition are micrococci, which likewise produce intes- 
tinal disorders when consumed by infants. Even when the udder 
inflammation is slight an increase in the number of leucocytes se- 
creted in the milk may be observed, and it was the recognition of this 
fact which has caused the introduction of microscopic examination 
of the milk for the determination of the presence or absence of garget. 
However, with the technique at present employed in the numerical 
determination of leucocytes there is too narrow a margin between the 
leucocytes found in the milk of healthy and those in diseased cows to 
make this form of diagnosis satisfactory and practicable. This is 
particularly true of milk from healthy cows during the first week of 
lactation, although at this time the normal increase of leucocytes 
would be accompanied by colostrum corpuscles. While the several 
