Report on the progress of human anatomy and physiology in the year 1842-3 / [Sir James Paget].

  • James Paget
Date:
1844
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Licence: Public Domain Mark

Credit: Report on the progress of human anatomy and physiology in the year 1842-3 / [Sir James Paget]. Source: Wellcome Collection.

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    the outer transparent, colourless, and resisting; the inner softer and less resisting. Between the two, or perhaps in the inner layer, the colouring matter is contained. The existence of a true nucleus in the corpuscles of the lower vertebrata is not by this rendered doubtful ; and Mr. Addison* * * § has shown, in the use of liquor potassa, a good method of demonstrating it in the corpuscles of the frog. Many interesting observations have been made by both Mr. Wharton Jones and Dr. Carpenter, in support of the view that some of the corpuscles of the blood are a kind of “ floating gland-cells.”f The former believes that the office of the red cor¬ puscles is to convert albumen into fibrin, elaborating it in their interior, and then, after the manner of gland-cells, dissolving and discharging their contents. The latter thinks it more probable that this office of converting the chemical compound into the organizable principle, is discharged by the pale corpuscles, and that the red corpuscles are the chief carriers of oxygen and carbonic acid The arguments of each may be found in the last October and January numbers of this Journal. Whichever view be most true, it may be received as highly probable, that the corpuscles in the blood are the agents by which, with the aid of the oxygen im¬ bibed in the lungs, the liquid portion is brought into a state fit for the nutrition of the tissues, and that this is their chief purpose. Mr. Macleod}; has described the development of the blood-corpuscles in the chick, dividing it into three stages. At first there are no particles in the blood except minute dark spherical granules. These gradually enlarge and become clear in their centres; but when they have arrived at the double of their original size, the central part of each becomes dull and then distinctly granular, while the border becomes defined, smooth, and clear. This completes the first stage, after which, in the second, the central granules disappear as if they had merged into one cen¬ tral clear nucleus, from which the external portion slowly separates, not at one side only, but all round. In this stage the corpuscle remains circular; but it becomes flatter, both on its surfaces and its edges, and a concave furrow forms between its outer border and the border of the nucleus. At the same time also it acquires colour apparently by the accumulation of colouring matter in the space between the nucleus and capsule. In the third stage, the corpuscle assumes the oval shape : first one side of both the cell and the nucleus gradually stretching out, and then the other, so that every part of the corpuscle becomes narrower except the middle. Coincidently with these changes, the furrow around the nucleus disappears, and the sharp edges of the borders are smoothly rounded off. Mr. Macleod believes that all these changes are effected by a power dwelling in the granules, each of which developes itself into a cell. He has never seen any congregation of granules to form a cell, nor any multiplication of granules within the once-formed nucleus, nor any opening in the centre of the nucleus, nor any escape of corpuscles from it.§ FiBRO-CELLULAR TISSUE. Dr Todd and Mr. Bowman|| have thrown doubt on the received opinion concern¬ ing the structure of the fibro-cellular tissue. They regard it not as consisting of bundles of parallel filaments of definite size and structure, but as a substance which * Transactions of the Provincial Medical and Surgical Association, vol. xi, p. 253. t See Report, Oct. 1812, p. 12. I London and Edinburgh Monthly Journal of Medical Science, Sept. 1842. § On the speedy and abundant development of microscopic vegetables (like those formed in fermenting fluids) in serum, or other albuminous fluids which have been neutralized by weak acids, diluted with water, and then exposed to the atmosphere, see MM. Andral and Gavarret’s ‘ Recberches sur le Developpement d’unVegetal microsc. dans les Liquides Albumineux,’ read at the Acad, des Sciences, Jan. 30, 1843, in the Gazette Medicate, Fevr. 11, 1813. There does not appear any ground for supposing that these vegetables (which are what Liebig supposed to be precipitated globules of albumen,) are, as some seem to think, a product of the blood; they are only formed under the same circum¬ stances as other analogous vegetables are in other fluids exposed to the air. ]| Physiological Anatomy and Physiology of Man, p. 69.