THE SPLEEN. 559 



color proceeds from unchanged blood-corpuscles, which may also be 

 readily expressed from the substance of the spleen and, on the addition 

 of water, in a short time lose all their coloring matter. In other ani- 

 mals the spleen, although it always has about the same, usually dark 

 color, yet contains in addition, sometimes only unchanged blood-cor- 

 puscles, sometimes multitudes of them in every stage of metamorphosis. 

 These are very striking, and in all animals consist essentially in this 

 that, 1, the blood-corpuscles, becoming smaller and darker and, in the 

 lower Vertebrata, losing their elliptical form and taking a circular shape, 

 agglomerate together into rounded masses, which either persist in this 

 condition, or, combined with a certain amount of the plasma of the 

 blood, develop an envelope externally and a nucleus in their interior, 

 thus passing into round blood- corpuscle- Fig. 231. 



holding sells, of 0-005-0-015 of a line, 

 containing 1-20 blood-corpuscles ; and 

 2, these masses and cells, their contained 

 blood-corpuscles gradually diminishing 

 in size and assuming a golden yellow, 

 brownish-red, or black color, either in 

 their entire state or after breaking up 

 into pigment granules, change into pig- 

 ment masses and pigmented granule cells; and, finally, the latter, their 

 granules gradually becoming pale, pass into perfectly colorless cells. In 

 many cases the blood-corpuscles form no masses or cells, but pass through 

 the above-described stages of coloration and disintegration, like the others.* 



FIG. 231. Blood-corpuscle-holding cells and their metamorphoses, from the spleen of the 

 Rabbit, magnified 350 diameters : a, two nucleated cells, with blood-corpuscles ; 6, similar 

 cells metamorphosed into brown pigment cells ; c, cells from which the color has disappeared 

 again ; d, pigment granules which have arisen from metamorphosed free blood-corpuscles. 



* [In his " Microscopical Anatomy," Prof. Kclliker states, that he has observed blood- 

 corpuscle-holding cells, and their breaking up into pigment granules, in the spleen of 

 almost all animals. In Mammalia the cells were generally seen with difficulty. In the 

 Cat, Horse, Ass, and Bat, no distinct cells could be detected, although the pigment masses 

 and the pigmented granule-cells were easily observable. In Birds he met with cells con- 

 taining blood-corpuscles only in the Blackbird although in many (Falco albicillus, Cuculus 

 canorus) he was able to detect yellow pigmented granule-cells changing into black pigment. 

 In the naked Amphibia and in Fishes, he frequently found cells enclosing 5 to 20 blood- 

 corpuscles, in which the metamorphosis into pigment could easily be studied. 



The " blood-corpuscle-holding cells" and the supposed result of their metamorphoses 

 pigment granules, are met with in great abundance in some of the diseases of the spleen. 

 Thus in atrophy of this organ the trabecula? and the parenchymatous structure are filled 

 with masses of a dark molecular pigment. In the enlarged spleen of typhoid and inter- 

 mittent fever, Heschl detected many pigmented granule cells and dark pigment granules. 

 It is probable that cells enclosing blood-corpuscles exist, not only in the spleen, but wher- 

 ever many blood-corpuscles and large masses of pigment are observed. I have seen cells 

 resembling " blood-corpuscle-holding cells" in melanosis of the eye, in congested lungs, 

 and as part of the peculiar dark granular matter, observed under the microscope, in the 

 black vomit of yellow fever. If in this last-named instance the cells were possessed of 

 distinct membranes or not, I was unable to determine. DaC.] 



