MINUTE ANATOMY OF THE CAPILLARIES. 281 



laries were invested by a cloudy layer of protoplasm, which 

 formed elongated fusiform bodies partly lying on the surface 

 an d partly imbedded in the substance of the membrane 

 Nearly coincidently in point of time, and apparently independ- 

 ently of each other, Hoyer,* Auerbach,-f myself,J and Aeby, 

 and more recently Chrzonszczewsky,|| have by means of nitrate 

 of silver shown that the wall of the capillaries is divisible into 

 nucleated areas. The action of the nitrate of silver is to colour 

 the substance intervening between the cells of a brown or black 

 tint, by which means the individual cells are brought into 

 strong relief, and may be then isolated by treatment with a 

 solution of potash containing 35 per cent, of the alkali (Aeby, 

 Eberth). 



A cellular structure was subsequently shown to exist in the 

 wall of the capillaries in almost all the organs of vertebrate as 

 well as of many invertebrate animals, both by myself 1F and by 

 Legros.** 



The plexus demonstrated by Fedenrff in and upon the capil- 

 lary walls, after treatment with nitrate of silver, is entirely 

 different from the foregoing, from which it is distinguished by 

 the irregularity of its meshes. Its nature has not been satis- 

 factorily ascertained. The form of the cells lining the capil- 

 laries varies to a considerable extent. As a general rule, it is 

 different in vessels of different calibre. Small capillaries pre- 

 sent cells that are more fusiform in shape ; large capillaries, 



* Archivfiir Anatomic, dated Jan. 18, 1865. 



f Breslauer, Zeitung, Feb. 17, 1865. 



j; Sitzungsberichte der Physikal. Medicin. Gesellschaft zu Wiirzburg, 

 Feb. 18, 1865; Medicinisches Centralblatt, No. 13, 1865; Tiber den JBauund 

 die Entwickelung der Slutcapillaren, Erste Abhandlung, " On the Structure 

 and Development of the Blood Capillaries, First treatise;" Wiirzburger 

 Natunvissenschaftliche Zeitschrift, Bandvi., 1866. 



Medicinisches Centralblatt, No. 14, 1865. 



j| Virchow's Archiv, Band xxxv., 1866. 



^[ Loc. cit., Ueber die Capittaren der Wirbellosen, " On the Capillaries of 

 Invertebrate Animals." 



** Legi os, Note surT Epithelium des Vaisseaux Sanguins, "Note on the 

 Epithelium of the Bloodvessels," Journal de VAnatomie et de la Physio- 

 logic, Cinquieme Annee, 1868, p. 275. 



ft Sitzungsberichte der Wiener Akademie, Band liii., 1866. 



