SPLEEN. 



783 



surrounds itself with a part of the blood 

 (plasma and globules), and, finally, con- 



Fig. 532. 



Cells containing blood corpuscles, from the spleen of the 

 Frog (Rana temporaria and esculenta), magnified 

 350 diameters. 



1, cells with one or more blood globules of an intense 

 yellow colour, diminished in size, yet mostly not 

 yet destroyed ; 2, cells with blood globules coloured 

 brown, orange, or black, still more diminished and 

 dissolved (coloured granule cells) ; 3, cells with 

 blood globules much diminished or quite dissolved, 

 and undergoing discolorization (pale-coloured 

 granule-cells) ; 4, cells with completely dissolved 

 and discolorized blood globules (colourless gra- 

 nule-cells) ; 5, coloured granule-cells (like those 

 in 3) in different stages of their transition into 

 black pigment-cells. 



In 1 5 the letters import, as in fig. 351. b, the 

 nuclei of the blood globules. 



ditionates the development of a membrane 

 on the surface of the sphere thus commenced. 

 Or one might regard the formation of spheres 

 consisting of some blood plasma and blood 

 globules as the primary phenomenon ; and that 

 then a nucleus begins in each sphere; and that, 

 finally, a membrane is thrown around these. 

 In corroboration of this opinion, Hasse and 

 myself* have observed in the pigeon the 

 occurrence of inflammatory globules, which 

 are without nuclei or membranes, but contain 

 blood globules ; and to this may be added, 

 that in the splenic extravasations blood cor- 

 puscles are often grouped together in heaps 

 without being contained in cells. Be this as 

 it may, in any case thus much is certain, that 

 as soon as the cells with their included blood 

 globules are visible, the nuclei are never 

 absent ; and this fact, taken in conjunction 

 with what is already known of the import of 

 nuclei in the process of cell development, 

 speaks strongly for their formation preceding 

 that of the membrane of the said cells. 



These cells containing blood corpuscles 



* Zeitschrift fur Ration. Medicin, Band. iv. S. 1. 



behave themselves so far alike in all creatures, 

 that their blood corpuscles by degrees dis- 

 appear and fall to the ground ; and, ulti- 

 mately, they all seem to be converted into 

 colourless cells, although the methods by 

 which this change occurs are different in 

 different animals ; whence it will be well to go 

 through them one by one. 



a. In mammals the cells with unchanged 

 blood corpuscles are not very easily seen, on 

 account of the small size of the latter, and 

 the facility with which they lose their colour ; 

 yet one can easily get a sight of them, pro- 

 vided the examination be made at the right 

 time, and the application of water forborne. 

 1 have seen them plainly in man, the rabbit 

 (Jig. 531. 1.), guinea-pig, sheep, calf, and dog; 

 and have found that in these creatures the 

 number of the included blood globules is 

 from 1 to 12, on an average from 2 to 6, 

 and the size of the cells from 5 to 16-1000ths 

 of a line; while their vesicular nuclei have a 

 length of 36-10000ths, and a breadth of 

 28-10000ths of a line. By the shrinking up and 

 falling to pieces of the blood globules, which 

 immediately renders them darker in colour, 

 coloured granule-cells begin from these cells. 

 They are of a golden yellow, or rusty or 

 brownish yellow, or even blackish colour 

 (yig.531.2.), and gradually experience a trans- 

 ition into cells, with slightly coloured, more 

 numerous, and smaller granules ; and, finally, 

 they take the form of altogether colourless 

 cells, part of which are even poor in granules 

 {fig. 531. 3.). In man, the rabbit, and the 

 guinea-pig were found, besides the cells just 

 described, free granules and heaps of granules, 

 of a golden yellow, brown, or blackish colour; 

 together with altered blood globules, con- 

 cerning which it seemed to me very probable 

 that they were originally free, and were never 

 included in cells. In other vertebrata, as in 

 the hedge-hog, the cat, and the bat (Vespertilio 

 myotis and pipistrellus), the cells with the 

 unchanged blood globules were not observed, 

 although all other stages, from the golden 

 yellow to the altogether colourless granule- 

 cells, were seen. Finally, in others, as in the 

 horse and ass, were seen uncommonly nu- 

 merous,diminished,and highly coloured blood- 

 globules, both isolated and aggregated ; and 

 the metamorphoses of these into golden, 

 brown, and blackish-yellow heaps of granules, 

 although no definite indication of cell struc- 

 ture could be detected around these heaps. 



b. Amongst birds, I have found the round 

 cells in Falco albicillus, Cuculus canorus, 

 Turdus varius, Perdix saxatilis, and Sylvia 

 hortensis. They were in larger or smaller 

 quantity, from 4 to 10-1000ths of a line in 

 size, with dark golden yellow granules which 

 were evidently nothing but metamorphosed 

 blood globules. This was very distinctly 

 shown in Turdus musica, since here the cells 

 occurred with unchanged blood globules. 

 Everywhere these cells experienced a trans- 

 ition, partly into brown and black granule- 

 cells, partly into colorless granulated cells. 



c. Amongst the Reptilia. In the scaly 



