THE HEART. 667 



with acetic acid are 'necessary. The smooth muscles of the areola are 

 found by mere dissection, although not always very easily, as, except 

 during pregnancy, they are frequently very delicate. 



Literature. Rudolphi " Bemerk. tiber den Bau der Bruste," in the 

 "Abh. der Berliner Akademie," 1831, p. 337; Astley Cooper, " The 

 Anatomy of the Breast," London, 1839, 4to ; C. Langer, " Ueber den 

 Bau und die Entwicklung der Milchdriisen, mit 3 Taf.," from the 

 "Derikschr. d. Wiener Akad.," Bd. III., Wien, 1851 ; A. Donn^, "Du 

 lait et en particulier du lait des nourrices," Paris, 1837; "Ueber die 

 mikroskopischen Korperchen im Colostrum" Muller's "Arch.," 1839, 

 p. 182; "Cours de Microscopic," Paris, 1844; Fr. Simon, "Die 

 Frauenmilch, nach ihrem chemischen u. physiol. Verhalten dargestellt," 

 Berlin, 1838 ; " Ueber die" Corps granuleux "von Donnd," in Muller's 

 "Arch.," 1839, pp. 10 and 187; J. Henle, "Ueber die mikr. Bestand- 

 theile der Milch," in Fror. "Notizen," 1839, No. 223; H. Nasse, 

 "Ueber die mikr. Bestandt. d. Milch," Muller's "Archiv," 1840, p. 

 259; Reinhardt, in "Arch. f. path. Anat.," Bd. L, pp. 52-64; Lam- 

 merts van Bueren, " Onderzoekingen over de Melkbolletjes," in the 

 " Nederl. Lancet," 2d ser., 4, Jaarg., p. 722, or " Observat. microscop. 

 de lacte," Traject. ad Rhenum, 1849, Diss. ; " De Ontwikkeling van 

 de Vormbestanddeelen der Melk," in the "Nederl. Lancet," 2d ser., 

 5, Jaarg, p. 1; Fr. Will, "Ueber die Milchabsonderung," Erlangen, 

 1850, Programm. Besides which should be consulted the " General 

 Anatomy" of Henle, J. Muller's work on the Glands, and the Atlases 

 of Berres, Donne', and Mandl. [ Vid. also, " Observations on the 

 muscular tissue of the Skin," by Joseph Lister, M.B., " Quart. Journ. 

 Micros. Sc.," vol. I., p. 262, 1853. TRS.] 



OF THE VASCULAR SYSTEM. 



212. The vascular system, consisting of the heart, with the blood 

 and lymphatic vessels, contains in its interior the blood and the lymph 

 (chylus), with innumerable morphological particles. The lymphatic vas- 

 cular system presents special organs the lymphatic glands. 



1. OF THE HEART. 



213. The heart is a thick, hollow, muscular organ, divided into four 

 compartments, invested externally by a serous membrane the pericar- 

 dium, and lined internally by the endocardium, a continuation of the 

 walls of the great vessels, particularly of the tunica intima. 



The pericardium does not differ in structure from other serous mem- 

 branes, as, for instance, the peritoneum. The outer lamella is consi- 



