CHANGES IN THE RED CORPUSCLES BY DESICCATION. 387 



opium, the red corpuscles of the blood do not retain their ordi- 

 nary average form in the mesenteric vessels, when driven 

 forward with the stream ; but become, during their flow, 

 more or less irregular in outline* If the current be re- 

 tarded or altogether arrested, or if the blood corpuscles are 

 compressed against each other or against the interior of the 

 vascular wall, they assume the same appearance as that which 

 we have above described as characteristic of the fresh blood 

 corpuscles. Moreover in diapaidesis, as it has been described 

 from direct observation by Stricker,f Prussak,j and others, 

 the phenomena we are now considering may be observed in the 

 red corpuscles during their transit through the vascular wall. 



Lastly, it is to be observed that the blood corpuscles, not- 

 withstanding their great extensibility, may be broken up by 

 mechanical means. This may easily be accomplished if a drop 

 of fresh blood be quickly expanded into a thin layer by the 

 pressure of a glass cover, which after the lapse of a few seconds 

 is raised, and again firmly pressed down ; there may then be 

 seen coloured spheroidal or discoidal fragments. In nucleated 

 corpuscles, as in those of the frog and triton, isolated nuclei are 

 often visible, which are usually round, frequently distorted, 

 and always granular. The number of the coloured fragments 

 is always small in comparison with these, proving that the 

 substance of the blood corpuscles becomes to some extent finely 

 distributed through, or actually dissolved in, the surrounding 

 fluid, which in point of fact appears slightly tinted. In anti- 

 cipation of observations hereafter to be mentioned, it must 

 be specially remarked that in these researches no shrivelled 

 colourless shreds were noticed representing remains of the 

 broken-down corpuscles. 



3. The characters presented by the blood corpuscles on 

 drying also deserve mention. C. Schmidt || has observed 

 that when a thin layer of blood corpuscles is dried upon glass, 



* Sitzungsberichte der -Wiener Akademie, Band 1., p. 196. 



f Loc. cit., Band lii., p. 386. 



I Loc. cit., Band Ivi., p. 13. 



Hensen, Zeitschrift fiir wissenschaftliche Zoologie, Band xi., p. 260. 

 Vintschgau, AttideW Institute Veneto. Extr. dal\o\. vii., ser. iii., pp. 3 6. 



|| Die Diagnostik verddchtiger Flecke. Mitau and Leipzig, 1848, p. 3, 

 et seq. 



