Volume 1

Elements of physiology : for the use of students, and with especial reference to the wants of practitioners / Tr. from the German, with additions by Robert Willis.

  • Rudolf Wagner
Date:
1841-2
Catalogue details

Licence: Public Domain Mark

Credit: Elements of physiology : for the use of students, and with especial reference to the wants of practitioners / Tr. from the German, with additions by Robert Willis. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    reddish-grey, finely-granular substance, and which, despite their minuteness, are seen to be round, three-cornered, taper-shaped, and so forth, and generally flattened in a greater or less degree. In the clear nucleus, which is ever relatively the larger as the ganglionic globule is absolutely smaller, from one to three sepa- rate nucleoli are contained. On the farther development of the ganglionic glo- bule, vide Miiller's Archiv, f. 1839. VI. The cells exhibit a very high degree of productive or procreative power. New nuclei are perpetually arising within them and there surrounding themselves with cells, we have finally cell within cell, like a nest of pill boxes (Repertor. i. 34, 175, 286, tab. ii. fig. 35) ; abundance of intercellular substance is at the same time de- posited betwixt the parietes of the cells, and these two elements blended together com- pose the elementary mass,—the cells with their products, the nuclei aud nucleoli, the proj)er and peculiar corpuscides. (Schwann, 1. c. 26, et sequent.) Cartilage.—This intercellular substance is more compact; it is granular in the permanent cartilages of the adult, and acquires its higher consistency and its earth in the process of ossification. During this there arise opaque, and by and by ossific reticulations, in the centre of which are seen clearer spaces, often sepa- rated by concentric annular striae, containing cartilage corpuscules with simple or double-imboxed nucleoli. These cartilage-corjouscules pass immediately into bone-corpuscules (Entwickel. 263); clear at first, they become more opaque by degrees; they are of large size, push out at one or both points, especially in the first instance, filiform prolongations, which are the first indications of radii, and grow of a darker hue from the periphery towards the centre. When they are still clear but chemically impregnated with lime, their structure is no longer recognizable; if the slice be softened by an acid, however, the nuclei and nu- cleoli come again into view, in the same way as the numerous smaller bone- corpuscules present themselves in the spongy tissue which surrounds the medul- lary cavity concentrically, or lengthwise, especially in the bones of adults, and like other cellular fibres contain elongated nuclei with pretty clear, small, and separate granules. On the formation of the medullary cavities, vide EntwickeU ungsgeschichte, 261. In the reticulate cartilage of the ear, the round granular nuclei and the intercellular substance blend together and form a network which hardens and enlarges, and besides the clear cellular substance, contains in its meshes round nuclei, or true cartilage-corpuscules. By reason of the multiplied imbo.ving in cartilage, the indication of the elements, as cell, nucleus, and nu- cleolus, is to be viewed as merely relative. On the fibres of the dental sub- stance, which Schwann (1. c. 74), with the greatest probability of being in the right, has referred to this ])lace, my own observations are incomplete. The cells of the primary mass resemble those of the primary substance of the auricular cartilage (in the sheep), and the fasciculate canals seem the analogues of the cellular parietes, or of these and the intercellular substance. * VII. The cells are tessellated, or spread out into a membrane, in the manner of a piece of pavement ; their granular nuclei lie in the middle. The parietes of the cells blend into a transparent simple membrane, whilst the nuclei are ever more and more absorbed J becoming constantly paler, until at length they are no longer recognizable : (a) Hyaloid MEMBRANE; capsule of tiik lens ; ei.kmuntary memurane OF THE SACcus cAPsuLo-puPILLARIS.—lu the first two of these tissues the nuclei are especially delicate ; their extreme paleness soon renders them scarcely visible ; by and by, as it appears, they vanish entirely.
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