THE LACTEAL GLANDS. 273 



at the time of lactation, undergoes peculiar metamorphoses. 

 All these glandular elements are surrounded by dense, white 

 connective tissue, particularly abundant between the gland- 

 vesicles and smaller lobules, Fig. 272. 

 and are united into a com- 

 pact, large glandular mass, 

 which is ultimately covered 

 by a quantity of adipose 

 tissue, and in part by the 

 skin. The lacteal glands 

 are, properly speaking, not 

 simple glands, but like the 

 lachrymal, aggregations of 

 these. From each glandu- 

 lar lobe, by the coalescence 

 of the excretory ducts of 

 the smaller and larger 

 lobules, there ultimately 

 proceeds a shorter or longer 

 duct, 1 — 2"' in diameter, 

 the lacteal duct or canal [ductus lactiferus s. galactophorus)> 

 which, running towards the nipple, dilates beneath the areola, 

 into an elongated sacculus, 2 — 4f" wide, the lacteal sac or 

 receptacle (sacculus s. sinus lactiferus) ; afterwards contracting 

 to 1'" or j"', it bends round into the nipple, and ultimately 

 opens, at its apex, in an independent orifice, not more than 

 I — J'" in diameter, between the papillce which exist in that 

 situation. All these excretory ducts, besides an epithelium, 

 which in the largest of them presents cylindrical cells, 0*006 — 

 001"' long, and in the finer ramifications, rounded, polygonal 

 smaller cells, and a homogeneous layer beneath them, also 

 possess a white dense fibrous membrane, longitudinally plicated 

 in the larger canals, in which I have hitherto been unable to 

 detect any indubitable muscular fibres, and nothing but a 

 nucleated, longitudinally fibrous, connective tissue with fine 

 elastic fibres. Henle, however, more recently, thinks that he 

 has noticed longitudinal muscles in the lacteal ducts, not those 

 of the nipple, but more deeply within the gland. 



Fig. 272. A few of the smallest lobules of the lacteal gland of a puerperal female, 

 with their ducts, x 70 diam. After Langer. 



11. 18 



