568 SPECIAL HISTOLOGY. 



20 per cent., is of service. The arteries and capillaries are easily in- 

 jected ; the veins with great difficulty ; most readily in Man. The 

 nerves are found with ease on the arteries ; the lymphatics may be best 

 studied in the Ox. 



Literature of the Spleen. M. Malpighi, " De liene," in " Exercit. 

 de vise, struct.," Lond., 16G9 ; J. Miiller, " Ueber die Structur der 

 eigenthiimlichen Korperchen in der Milz einiger pflanzenfressenden 

 Thiere," Muller's "Archiv," 1834 (the first good anatomical work 

 since Malpighi) ; T. C. H. Giesker, " Splenologie, I. anatomisch. phy- 

 siologische Untersuchungen liber die Milz," Zurich, 1835 (a very ela- 

 borate treatise) ; Schwager-Bardeleben, " Observationes micros, de gland, 

 ductu excretorio carentium structura," Berol., 1841 ; Th. von Hessling, 

 "Untersuchungen iiber die weissen Korperchen der menschlichen Milz," 

 Regensburg, 1842; A. Kolliker, "Ueber den Bau und die Verrich- 

 tungen der Milz," in Mittheil. " Der Ziirch. nat, Gesellschaft," 1847, 

 p. 120; "Ueber Blutkorperchen haltige Zellen," in "Zeitsch. fiir wiss. 

 Zool.," Bd. I. p. 261, and Bd. II. p. 115; art. "Spleen," in Todd's 

 " Cyclopaedia of Anatomy," June, 1849 ; A. Ecker, " Ueber die 

 Veranderungen, welche die Blutkorperchen in der Milz erleiden," in 

 "Zeitsch. fiir Rat. Medicin," VI. 1847, and art. " Blutgefassdriisen," 

 in R. Wagner's "Handw. der Phys.," IV. 1, 1849; J. Landis, "Bei- 

 trage zur Lehre iiber die Verrichtungen der Milz," Zurich, 1847 ; Ger- 

 lach, "Ueber die Blutkorperchen haltenden Zellen der Milz," in 

 " Zeitschrift fiir Rat. Medicin," VII. 1848; " Gewebelehre," p. 218 ; 

 R. Sanders, "On the Structure of the Spleen," in Goodsir's "Annals 

 of Anat.," I. 1850; 0. Funke, "De sanguine venae lienalis," Lips., 

 1851. 



[Gray, " On the Development of the Ductless Glands in the Chick," 

 "Phil. Trans.," 1852. TRS.] 



OF THE RESPIRATORY ORGANS. 



171. Under the head of respiratory organs are usually enumerated 

 only the larynx, trachea, and lungs ; but I consider it as most suitable 

 here to describe two organs connected genetically with those respiratory 

 organs of the embryo, which remain undeveloped, that is to say, the 

 branchial arches ; and which, physiologically, perhaps, belong to the 

 lungs the thyroid gland and the thymus. 



OF THE LUNGS. 



172. The structure of the lungs corresponds, in all respects, with 

 that of a compound racemose gland, presenting, in the lobes, lobules, 

 and air-cells, the proper glandular parenchyma ; whilst the bronchice, 



