338 



SECRETION. 



COLOSTRUM. 



Near the end of uterogestation, during a period which varies considera- 

 bly in different women and has not been accurately determined, a small 

 quantity of a thickish, stringy fluid may frequently be drawn from the mam- 

 mary glands. This bears little resemblance to perfectly formed milk. It is 

 small in quantity and is usually more abundant in multiparae than in primi- 

 parge. This fluid, as well as that secreted for the first few days after delivery, 

 is called colostrum. It is yellowish, semi-opaque, of a distinctly alkaline re- 

 action and is somewhat mucilaginous in its consistence. Its specific gravity 

 is considerably above that of the ordinary milk, being between 1040 and 1060. 

 As lactation progresses, the character of the secretion rapidly changes, until 

 the fluid becomes filled with true milk-globules and assumes the characters 

 of ordinary milk. 



The opacity of the colostrum is due to the presence of a number of differ- 

 ent corpuscular elements. Milk-globules, very variable in size and number, 

 are to be found in the secretion from the first. These, however, do not exist 

 in sufficient quantity to render the fluid very opaque, and they are frequently 

 aggregated in rounded and irregular masses, held together, apparently, by 

 some glutinous matter. Peculiar corpuscles, supposed to be characteristic of 



the colostrum, always exist in this fluid. 

 These are known as colostrum-corpus- 

 cles. They are spherical, varying in 

 size between g ^ 0() and -^^ of an inch 

 (10 and 50 /x.), are sometimes pale, but 

 more frequently quite granular, and 

 they contain very often a large number 

 of fatty particles. They behave in all 

 respects like leucocytes and are de- 

 scribed as a variety of these bodies. 

 Many of them are precisely like the 

 leucocytes found in the blood, lymph 

 or pus. In addition to these corpuscu- 

 lar elements, a small quantity of mucine 

 may frequently be observed in the co- 

 lostrum on microscopical examination. 

 On the addition of ether to a speci- 

 men of colostrum under the microscope, 

 most of the fatty particles, both within 

 and without the colostrum-corpuscles, 

 are dissolved. Ammonia added to the fluid renders it stringy, and sometimes 

 the entire mass assumes a gelatinous consistence. 



In its composition, colostrum presents many points of difference from 

 true milk. It is sweeter to the taste and contains a greater proportion of 

 sugar and of the inorganic salts. The proportion of fat is at least equal to 

 the proportion in the milk and is generally greater. Instead of caseine, pure 



FIG. 104. Colostrum, from a healthy lying-in 

 woman, twelve hours after delivery (Funke). 



The smaller globules are globules of milk. The 

 larger globules, a, a, filled with granula- 

 tions, are colostrum-corpuscles. As lacta- 

 tion advances, the colostrum - corpuscles 

 gradually disappear, and the milk-globules 

 become more abundant, smaller and more 

 nearly uniform in size. 



