THE BOOK OF THE DAIRY. 



CHAPTER I. 



THE SECRETION, PROPERTIES, AND COMPOSITION OF MILK. 



1. Definition. By milk, 1 in the widest sense of the term, is 

 understood the secretion of the special glands of the female mammal. 

 It is a white, opaque liquid, of the character of an emulsion, with 

 a faint odour and 



a slight flavour; 

 and it is produced 

 during a longer 

 or shorter period 

 after parturition. 

 It consists chiefly 

 of water, fat, case- 

 in, albumin, milk- 

 sugar, and mineral 

 salts, and is spe- 

 cially adapted for 

 the sustenance of 

 the young. 



2. The Cow's 

 Udder. The par- 

 ticular glands in 

 which the milk ori- 

 ginates the milk 

 glands form the 

 most important 



portion of the milk-secreting udder (see plates of cow's udder, figs. 

 1 and 2). The cow's udder is divided into two by a strong fibrous 



1 By the term milk is always to be understood whole milk, and not skimmed milk. 

 ( M 175 ) 1 A 



3. Structure of 

 Cow's Udder. 



Bundle of Elastic Fibres (a), and Connective Tissue Fibres (&). 

 (x200.) (Fiirstenberg.) 



