THE LACTEAL GLANDS. 665 



less disintegrated fatty cells, exactly resembling the subsequent milk- 

 globules, and also contains such cells either with or without a tunic 

 the so-termed colostrum corpuscles. On the commencement of lactation 

 after parturition, the cell-formation in the gland-vesicles proceeds with 

 excessive energy, in consequence of which the secretion collected in the 

 lactiferous ducts and gland-vesicles is evacuated, as the colostrum or 

 immature milk, the true milk taking its place. 



The latter, in the extremities of the gland, consists only of some 

 fluid and cells entirely filled with fat-globules, which sometimes occupy 

 the gland-vesicles alone, sometimes associated with pale epithelial cells, 

 which, however, always contain more or less fat, and originate either in 

 a free cell-formation or from epithelial cells, in a way analogous to that 

 in which the cutaneous sebaceous matter is formed (vide 73), by their 

 continued multiplication. These cells, which I would designate milk- 

 cells, break up, so soon as they reach the lactiferous ducts into their 

 elements, the milk-globules ; the membrane, and for the most part also, 

 the nucleus, disappearing, without a vestige being left, so that the 

 milk, when secreted, usually presents no indication of its mode of 

 origin. At most, there occur in it a very few larger or smaller aggre- 

 gations of milk-globules, which, from their similarity to those met with 

 in the colostrum, may likewise be termed colostrum-corpuscles. The 

 secretion of the milk, therefore, depends essentially upon a formation 

 of fluid and fat-containing cells in the gland-vesicles, and consequently 

 falls into the category of those secretions into the composition of 

 which morphological elements enter ; above all to the fatty secretions, 

 such as the cutaneous sebaceous matter, in which cells of precisely 

 similar kind occur to those met with in the gland-vesicles of the lacteal 

 glands, and in the colostrum. 



In the new-born child, the mammary gland very frequently contains 

 a small quantity of a fluid presenting the external and microscopical 

 characters of milk, the origin of which is probably related to the 

 formation of the glandular ducts. 



With respect to the colostrum-corpuscles and fat-globules of the 

 colostrum, Reinhardt was the first to prove, - that the supposition 

 broached by Nasse and Henle, that these bodies are related to a forma- 

 tion of fat-containing cells in the mammary glands, and that the former 

 in their more usual form are nothing but membraneless cells, and the 

 latter oil-drops liberated from cells, is in every respect well founded, 

 although he is inclined to distinguish the formation of the colostrum 

 from the secretion of milk, and to regard the former as a pathological 

 process, as a fatty metamorphosis, by which the old epithelial cells of 

 the gland, previously to the formation of true milk, are evacuated 

 externally, and particularly because, in the true milk-formation, he 



