374 INVESTIGATION OF THE SPLEEN. [sect. 1 70. 



the whole spleen, develop themselves in the third month, partly into 

 vessels and fibres, while a part remains as the cells of the paren- 

 chyma. The Malpighian bodies are of later growth, but they are 

 seen, without exception, at the end of the foetal period, although 

 considerably smaller then than at a subsequent time. I do not 

 know for certain how they originate, but I believe them to be 

 produced from little masses of cells, the outermost of which de- 

 velop into the fibrous envelope; while those of the interior remain 

 partly in their original condition, partly are metamorphosed into 

 blood-vessels. 



This is not the proper place to discuss at length the functions of 

 the spleen, for which I refer the reader to my Micros. Anat., ii. 2, 

 p. 282. Here I shall content myself by observing, that the most 

 recent observations ( Wilrzh. Trans., vii.) tend to show that the 

 spleen is essentially an organ in which colourless and also coloured 

 blood-corpuscles are developed, which, after having been taken up 

 by the veins of the organ, are in this manner mixed in the blood. 



The investigation of the spleen presents, as far as certain conditions are 

 concerned, no difficulties ; the pulp, trabecule, envelope, and Malpighian 

 corpuscles are found without any preparation. The Malpighian bodies are 

 best examined first in the pig and ox, for in these animals the envelope and 

 contents can be readily isolated, and the connexion with the vessels may also 

 be seen. In order to see cells containing blood-corpuscles, the addition of 

 water must be avoided. The muscular fibres may be very distinctly seen in 

 the finer trabecule of the ox, pig, and dog, especially after maceration in 

 nitric acid of 20 per cent. Injections of the .arteries and capillaries can be 

 readily made, the veins being difficult to inject ; in-the lower animals, even 

 more difficult than in man. The nerves are readily found upon the arteries ; 

 the lymphatics are to be studied in the ox. In the examination of the pulp 

 Billroth uses liq.ferri sesquichl., and in man, chromic acid and glycerine. 



Literature. — M. Malpighi, Dc Liene, in Exercit. de Vise. Struct., Lond., 

 1669. J. Muller, in his Archiv., 1834. T. C. H. Giesker, Splenologie, i., 

 Zurich, 1835. Schwagen-Bardeleben, Obscrvationes Micr. de Gland. Ductu 

 Excretorio Carentium Structvrd, Berol., 1841. Th. v. Hessling, Untersuchungen 

 iiber die weissen Korperchen der menschlichen MHz, Regensburg, 1842. A. 

 Kolliker, in Mittheil. der Zurich, nat. Gesellschaft, 1847, p. 120. In Zeitschrift 

 fiir wiss. Zool., vol. i., p. 261, and vol. ii., p. 115. Wilrzburg. Verh., Bd. iv., 

 p. 58. Art. Spleen, in Todd's Cyclopaedia of Anatomy, June, 1849. A. Ecker, 

 in Zeitschrift fur rat. Medicin, vi. 1847. Art. Blutgefassdriisen, in R. 

 Wagner's Handw. der Physiol., iv. 1, 1849; and Icones Phys., tab. vi. J. 

 Landis, Beitrage zur Lehre iiber die Verrichtungen der MHz, Zurich, 1847. 

 Gerlach, in Zeitschrift fiir rat. Medicin, vii. 1848. Gewebelehre, p. 218. R 

 Sanders, in Goodsir's Annals of Anat., i. 1850. 0. Funcke, De Sanguine 

 Venai Lienalis,IAj)s., 1851. W. O. Chalk, in Med. Times, July, 1852. Sanders, 

 in Monthly Journal, March, 1852. Vl. Hlasek, Disquis. de Struct. Lienis., 

 Dorp., 1852. H. Gray, On the Development of the Ductless Glands, in Phil. 



