554 



SPECIAL HISTOLOGY. 



Fig. 229. 



estimating the number of the Malpighian corpuscles to assume that every 

 1-1J cubic line of the pulp contains a corpuscle. 



With respect to its minute structure, every Malpighian corpuscle 

 possesses a special coat and contents, and is therefore a vesicle. The 



membrane is colorless and transparent, 

 0-001-0-002 of a line thick, and every- 

 where exhibits a double contour, with 

 occasional intermediate concentric lines ; 

 it is intimately connected with the sheath 

 of the vessel, with which it also agrees 

 in structure, so far as it contains homo- 

 geneous connective tissue and elastic fibrils ; 

 whilst, on the other hand, the smooth 

 muscles which are also present as longi- 

 tudinal fibres in these sheaths, are entirely 

 absent. In their interior, the Malpighian corpuscles contain no epithe- 

 lium, but are entirely filled by a viscid, grayish, continuous substance, 

 consisting of a small quantity of a clear, neutral fluid, coagulable by 

 heat, and therefore albuminous ; of many, rounded, larger and smaller 

 (from 0'003-0*006 of a line), pale cells, which usually possess a single 

 nucleus and become granulated by the action of water 

 and of a varying number of free nuclei. Besides these 

 cells, which frequently contain single fat-granules and 

 offer the most distinct evidence that in the Malpighian 

 corpuscles a constant development of cells is going on, we 

 occasionally meet with blood corpuscles, either free or in 

 cells and, as I am inclined to believe from a single observation in the 

 spleen of a Cat, with fine bloodvessels, as in Peyer's follicles (see 155). 

 The Malpighian corpuscles are completely closed, and are not con- 

 nected with the lymphatics, although this has been assserted by 

 different authors among the moderns by Huschke, Gerlach, Pb'lmann 

 and Schaffner. Anatomically, they are perfectly similar to the follicles 

 of Peyer's patches, and of the solitary glands, described above, and 

 very closely agree with those of the tonsils and lymphatics, whence 

 they may for the present be denominated gland-like follicles.* 



FIG. 229. A Malpighian corpuscle from the spleen of an Ox, magnified 150 diameters: 

 a, wall of the corpuscle; 6, contents; d, sheath; and e, wall of the artery to which it is 

 attached. 



FIG. 230. Contents of a Malpighian corpuscle from the Ox: a, small ; b, large, cells; c, 

 free nuclei. 



* [In a case of suicide, Prof. Kdlliker (Wiirzb. Verhand. IV. 1) has lately detected distinct 

 capillaries within the Malpighian corpuscles. Capillaries within the corpuscles he had 

 hitherto only seen in the spleen of a Cat ; they have, however, from independent obser- 

 vations, already been described by Gerlach and Huxley as occurring in Man. 



The Malpighian corpuscles undergo, in some diseases, a peculiar degeneration. Thus, in 

 the disease termed " waxy," or " colloid" spleen, they present the appearance of gelatinous 



