52 THE AMERICAN MONTHLY [March, 



wise the suspensory Hgament sends attachments forward to the skin, and 

 behind along the whole pectoral aspect. 



The gland itself consists of many lobes, made up of lobules bound together 

 by connective tissue, supplied with blood-vessels, nerves, and Ivmphatics. 

 The ultimate lobules consist of foliated vessels, the true secreting portion of 

 the gland, termed acini, or glandules, which open into the smallest of the 

 lactiferous ducts, these uniting form larger ducts, which finally end in a 

 single canal. These converge toward the areola, beneath which they form 

 dilatations, which act as reservoirs for the secretion ; from these they become 

 contracted and follow out to the nipple a straight course, opening upon the 

 external surface bv an indefinite number of orifices. 



It is characteristic of the mammai'y gland that it is subject to varying 

 changes, normal, idiythmic, and directed toward a definite end. To ap- 

 preciate these changes in the parturient female, the condition of the gland in 

 the embrvo must receive attention, for its formation is an embryonic act, 

 and upon the birth of the foetus, the result of formative and functional ac- 

 tivity is found in the breast of the babe. 



The structm^e in the embryo will be found to exhibit a series of changes, 

 which may be compared with the successive changes of a periodical rise into 

 activity. 



The acinus in embrvonic development is believed to begin as a small group 

 of cells, at first nuclear, but afterward invested with a quantity of cell sub- 

 stance. The circular boundary of the acinus is next determined by a vacuolation 

 of the cells. The vacuolated cells burst their membranous walls, and dis- 

 charge their contents ; the evacuated fluid being the* secretion of the mammary 

 o-land of the fretus. The same result follows in pregnancy, the acini undergo 

 a developing process, and, when the term is ended, a fluid is discharged in 

 a larger quantity. 



The embrvonic tlevelopment of the gland is an epitome of subsequent 

 structural and functional states of rest and activity. 



Rest, or functional inactivitv of the cellular elements, means complete 

 shrinkage of acini, partial obliteration of the ducts, and a proliferation of the 

 connective tissue between the lobules. Incited by the irritation of uterine 

 functional changes, the future condition of the gland is one of progressive 

 activity, coincident with the beginning of pregnancy and occupying the entire 

 period of gestation. 



The progress of the activity ot the gland is attended by a gradual assump- 

 tion of cellular individuality, the marked enlargement of the whole contour 

 of the gland, the lobules full and round, the fibrous trabeculge thin and having 

 now a secondary position. The floor of the acini is covered with a laj-er of 

 cells, in more or less regular order. 



The milk of the first seventy-two hours after parturition is known as co- 

 lostrum, it being the result of fatty degeneration of the innermost cells of the 

 acini, and their downfall leaves a cavity, afterward to be filled with milk ; 

 the physiological degeneration of epithelial tissue looking toward a specific 

 end. 



Notices of New Methods.— II. 



By GEORGE C. FREEBORN, 



NEW YORK CITY. 



Celloidin-Paraffin Imbedding.* Kultschizky. — The specimens are 

 placed, from alcohol, in a mixture of equal parts of alcohol and ether for 

 one hour. Then for twenty-four hours in a strong solution of celloidin. 



* 3 f. w. Mikros., iv, p. 48, 1887. 



