2IO NERVOUS SYSTEM. [sect. 108. 



stellate bodies with delicate walls. The natural conditions of the lacunae 

 may be readily seen in thin sections of perfectly fresh bones, or in thin 

 bone-lamellse, as, for example, in many parts of the facial bones. In fresh 

 bones, the vessels may be studied with the microscope, as they are naturally 

 injected with blood. In this way the wished-for object is much more readily 

 obtained than by artificial injections, which often fail, and in which, in order 

 to permit of more close investigation, the bones must be subsequently de- 

 calcified in hydrochloric acid, and preserved in oil of turpentine. The nerves 

 are found with the naked eye upon the nutrient arteries of the large cylin- 

 drical bones, and on smaller vessels with the aid of the microscope ; those of 

 the periosteum are to be studied after the tissue has been rendered trans- 

 parent by caustic soda or acetic acid. For the study of the cartilage, the 

 costal and articular cartilages are best adapted ; in these, the cartilage-cap- 

 sules partly present themselves to view without further treatment, partly 

 after addition of acetic acid and caustic soda, which clears up the matrix. 

 By boiling and maceration, the cartilage-capsules are readily isolated, and 

 they naturally so occur in the yellow cartilages, especially in the large mam- 

 malia. The development of the bones may be investigated in a cylindrical 

 bone and in a parietal bone, the formation of the lacunse in rachitic bones, 

 and upon the osseous surfaces of the symphyses and synchondroses. 



Literature. — In addition to the works ci+ed in § 5 and § 10, the following 

 may be consulted: — Votsch, Die Heilung dcr Knochenbriiche, per primam 

 Intentionem. Heidelberg, 1847. Kolliker, Ueber Verhnocherung bet Rachitis, 

 in Mitth. dcr Zicrch. nat. Gesellsch. 1847, p. 93. Rokitansky, in Der Zeitsehrijt 

 d. Wiener Aertze, 1848, p. 1. A. Krukenberg, in MiiLL. Arch., 1849, p. 403. 

 H. Meyer, in Mull. Arch., 1849, P- 2 9 2 - Virchow, in Vcrhandl. der Wurzb, 

 Phys. Med. Ges., Bd. i. No. 13. Robin, in Mem. dc la Societe de Biolog., 1850, 

 p. 179. J. Tomes and Campbell be Morgan, Obs. on the Struct, and Developm. 

 of Bone, in Phil. Transact., 1853, i., p. 109. Branbt, Disqvis. de ossijic. Pro- 

 ccssu. Dorp., 1852, Diss. Bruch, Beitrdge wr Entwickelung des Knochen- 

 4§stcms, in Denhschr. d. Schweiz. Nat. Gesellsch., xii. ' Virchow, Das normale 

 Waclisthvm und die rachitisehc Stoning derselben, in s. Arch., iv., p. 409. H. 

 Meyer, Beitrag z.Lehre von den Knochenliranlthciten, in Zeitschr.J. rut. Med., 

 iii, 1853, p. 143. 



Of the Nervous System. 



§ to8. The nervous system, regarded from an anatomical point 

 of view, is a completely connected wliole, in which two principal 

 masses may be distinguish eel, the spinal cord and brain, and nu- 

 merous cords proceeding from them to almost all parts of the 

 body, the nerves. The two former, constituting the central nervous 

 system, are not only to be regarded, from an anatomical point of 

 view, as giving origin to the nerves, but also, physiologically, as 

 excitors of movement, and as the seat of sensations and psychical 

 actions; whilst to the latter, or the peripheral nervous system, a 

 more subordinate office is ascribed, that of serving as intermediate 

 or connecting parts in the production of sensation and motion. 



