OF THE DUCTLESS GLANDS: THE SPLEEN. 457 



l-3000th of an inch in diameter. Besides these and other varieties of cells con- 

 tained in the Malpighian corpuscles, Dr. Sanders describes a peculiar set of 

 spherical cells, of a bright golden color, usually from l-1200th to l-1500th of 

 an inch in size, each having a single nucleus; which cells form a regular layer 

 beneath the capsule. Among these are seen other cells of 1-1 000th of an inch 

 or more in diameter, containing two or three nuclei; and yellow globules of all 

 diameters from 14000th to l-12000th of an inch, which are probably either 

 free nuclei or young cells of this class. Between the corpuscular contents of 

 the Malpighian corpuscles, there intervenes a homogeneous or slightly granular 

 plasma. The remarkable discovery has recently been made by Dr. Sanders, that 

 the interior of the Malpighian corpuscles is traversed (like that of the Peyerian 

 vesicles, 456) by arterial twigs of considerable size; which may be demon- 

 strated by boiling the tissue in acidulated water, drying it, and then cutting thin 

 sections. 1 Many observers have affirmed that there is some special connection 

 between the Malpighian corpuscles and the Lymphatics of the spleen ; but it 

 may be considered as quite determined by the concurrence of the most recent 

 observations on this point, that no such communication exists. 



IV. The true Splenic Parenchyma consists in great part of cells, which cor- 

 respond in appearance with those of the Malpighian corpuscles, and which are, 

 like them, imbedded in a nearly homogeneous plasma ; but two other kinds of 

 cells occur in it, which are seldom met with in the latter; and numerous free 

 nuclei are also present. Of these two kinds of cells, one set is smaller, and the 

 other larger, than the average of the parenchymatous cells; the former bear a 

 strong resemblance to red blood-corpuscles, but are of a paler color; the latter 

 are partly pale cells, of 1-1 700th of an inch in diameter, with one or two 

 nuclei, or granule-cells of from l-3000th to l-2000th of a line, which may 

 be described as "colorless granule-cells." These elements of the pulp, like the 

 contents of the Malpighian corpuscles, vary greatly in their proportions to each 

 other; from which it may be concluded that they are in a state of continual 

 development and degeneration. They do not lie collected in large heaps, but 

 form small irregular groups of different sizes, which are clustered especially on 

 the sheaths of the vessels, the trabecular partitions, and the membranes of the 

 Malpighian corpuscles ; they are not themselves included, however, in special 

 envelops. Besides the usual corpuscles and granules of the parenchyma, it 

 contains dispersed through it, in very inconstant amount, some remarkable 

 colored particles, varying from the size of small granules to that of blood-corpus- 

 cles, and often aggregated in masses of l-1000th of an inch in diameter, having 

 a distinct envelop which sometimes contains as many as twenty corpuscles. 

 These are probably, as asserted by Kolliker, blood-corpuscles in various stages 

 of degeneration; but they are by no means peculiar to the spleen, for they present 

 themselves in many other situations where extravasations of blood occasionally 

 occur ; and, as remarked by Dr. Sanders, " from all the circumstances connected 

 with them, they would appear to be the product, not of organic processes, but of 

 physical alteration in stagnant blood, and are only more abundant in the spleen, 

 because more blood is retained after death in its pulp, than in the substance of 

 other organs." 



V. Of the Splenic Arteries, it is chiefly to be observed that their branches 

 form no anastomoses, but that they subdivide and ramify like the branches of a 

 tree, with the Malpighian corpuscles attached to them as fruit. Beyond their 

 connection with these, however, they enter into the red spleen substance; and 

 here each twig subdivides into a tuft of arteries still more minute, which again 

 subdivide into the true capillaries that constitute a close and beautiful network 

 in the splenic pulp. Of the Veins, it is positively affirmed by Prof. Kolliker, 



1 See " Edinburgh Monthly Journal," March, 1852, p. 286. 



