Licence: Public Domain Mark
Credit: A text book of physiology / by William Rutherford. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
70/180 (page 58)
![Coloured Blood-Corpuscles of Man.—The human coloured cor- puscle is a convenient example of the non-nucleated red corpuscle. Viewed edgewise, it is flattened and biconcave (Fig. 16, h). When lying on its broad surface it has a circular shape (a), and, being bicon- cave, it has a shadowed centre surrounded by a light ring, or the reverse, according as the concave centre or the convex margin is brought into focus. It has a smooth surface, is transparent, and of a jiale yellow colour. When withdrawn from the circulation the corpuscles usually run together into piles (rouleaux) (c). The Effects of Eeagents on Coloured Blood-Corpuscles of Newt and Man are important because of the indications they give of the structure and chemical composition of the corpuscles. Their effects will be better understood if it be previously stated that the coloured coq^uscle has a thin, clear, soft, extensible, but perfectly elastic envelope, as indi- cated by Schwann, though many have erroneously disputed his statement. The pigment lies outside the nucleus, in the nucleated corpuscles,—and it is very generally believed that it fills the meshwork of a colourless, soft, elastic, thread-like (Hensen, Oj). 38, vol. i. 409), or sponge-like (Briicke, RoUett, O]). 38, i. 410) stroma, that stretches from the envelope through- out the interior of the corpuscle. The existence of the stroma can scarcely be held as definitely proved, but it seems necessary to explain the persistent maintenance of a definite shape by the non-nucleated corpuscle. Magenta solution reddens the nucleus of the newt's corpuscle, and also reddens one—rarely two minute swellings in the wall of the corpuscle. In the human corpuscle the latter is the only part that is stained (Fig. 22, /). The significance of this coloured macula in the envelope, discovered by Roberts {Op. 4, vol. xii. 481), is altogether obscure. The fact that it. occurs in the nucleated, as well as in the non-nucleated corpuscle, prevents the supposition that in the latter it is to be regarded as a shrivelled nucleus. Water.—When water is added to the newt's corpuscles, they lose, their- flattened shape, and become ovoid and sometimes spherical. This seems to be due to softening of the stroma and envelope, and to imbibition. The pigment may gather around the nucleus, but usually it diffuses into the sur- rounding fluid, leaving the cor- puscle colourless. The nucleus may also swell up : sometimes it Fig. 19. Red blomi - corpusoles of newt alteied by remains withiu the COrpUScle (Fig. water, n, Coi-piisele with retained, b, with discharged, qj. moveS tO the side, and ^ becomes partially or completely discharged. In the latter case no rent remains in the envelope, probably because it is a colloid membrane, somewhat like that of a soap-bubble. Event- ually the envelope may dissolve and disappear. When the human corpuscle is acted on by water it becomes spherical. The shadowed spot is therefore lost. The colour vanishes, and the corpuscle may eventually disappear. Dilute Alcohol (rectified spirit one part, water two parts, Ranvier) causes the newt's corpuscle to swell and lose colour. The nucleus also becomes](https://iiif.wellcomecollection.org/image/b21981747_0070.jp2/full/800%2C/0/default.jpg)
