362 



MALPIGHIAN CORFUSCLES. 



[sect. 167. 



Fig. 154. 



With regard to their intimate structure, every Malpighian cor- 

 puscle consists of matters contained within a special envelope, and 

 is, accordingly, a vesicle. The membrane is colourless, transparent, 

 o"ooi'" to croo2'" thick, and is everywhere bounded by a double 

 contour, in which there occasionally appear concentric lines. 

 It is intimately connected with the sheath of the vessels, and so 

 far resembles this in structure, that they both contain a homo- 

 geneous connective tissue and elastic fibres. On the other hand, 

 the smooth muscular fibres, which, in many animals, are found 

 running longitudinally in the sheaths of the vessels, are completely 

 absent from the membrane of the Malpighian body. These cor- 

 puscles contain no epithelium in their interior, but are stuffed with a 



viscid coherent substance, of a 

 greyish-white colour. This is 

 composed of a multitude of cells 

 in a small quantity of fluid. The 

 fluid is clear and neutral; it is 

 coagulable by heat, and is, there- 

 fore, albuminous. The cells are 

 pale, roundish, vary in size from 

 0'0Q3'" to o*oo6'", and most of 

 them have but one nucleus ; these 

 cells are rendered granular by 

 water. There is also a variable 

 number of free nuclei, which, how- 

 ever, were wanting in my most 

 recent experiments, made Avith great care ; all free nuclei having 

 been derived from the rupture of the cells. The cells frequently 

 contain separate fat granules, and they furnish very distinct 

 proof that a continual process of cell -formation is going on in the 

 Malpighian bodies. Besides the cells, blood-corpuscles are also 

 found in particular instances in these bodies, sometimes altered, 

 sometimes unaltered, free or enclosed in cells. Fine hlood-vessels 

 are also found, as in the follicles of Peyer's glands (see above). 

 This observation was first made by myself on the spleen of a cat 

 in the year 1852, and has since been confirmed by Sanders in 

 the pig, by Gerlach in the sheep, by Leydig in the coluber, and by 

 myself in man. 



The Malpighian corpuscles are completely closed sacs, and are 

 related anatomically to the follicles of the Peyerian and solitary 

 glands, already described, and also to those of the tonsils and 

 lymphatic glands. On this account, they may, for the present, 



A Malpighian corpuscle, from the spleen of 

 the ox; magnified 150 times, a. Wall of the 

 corpuscle, b. Contents, e. Wall of the artery, 

 upon which it is seated, d. Sheath of the 

 same. 



