Report on the chief results obtained by the use of the microscope, in the study of human anatomy and physiology / [Sir James Paget].

  • James Paget
Date:
1842
Catalogue details

Licence: Public Domain Mark

Credit: Report on the chief results obtained by the use of the microscope, in the study of human anatomy and physiology / [Sir James Paget]. Source: Wellcome Collection.

    12/60 (page 8)
    and the semiiiiil corpuscles, and the corpuscles of several other ^hinds may be placed in the same list of secondary intra-celliilar formations. ’ In another case belonging to this division, the cells, instead of arraiiP-inff themselves in rows and coalescing end to end, lie scattered at some distance from each other, and, sending out processes from their sides into the surrounding cy toblastema, assume the shape of radiating cavities. Their processes coalescing tliey become a network of canals, in which the differences of caliber which ft to thtlM? nfn JT ' mentioned, according to whicli It must be in a measure modihed. In it the nucleus is supposed tS tlt^iXl\'sHte''if precedent of the cf 11; when •IS I’l n n n* • attained, the nucleus is supposed to be absorbed mXfble vegetable tissues But it seems more piobable, that m the production of many animal tissues, the nucleus has a more important part to perform. In Dr. Barry’s system (examples of whicii tlnn\‘'lirre‘ll'^ ‘”hpT '''‘s it greatei- share in development of he m.cfe is f persistence and further development 01 the Qhcleus are frequent, and enumerates as the only parts in wliich t dis- irSrk rthe7‘‘hTP“f '^Pitlennifa’^nd nails, and mLrof the tat cells, the tubules of the lens and enamel, the bone-, and some of the car he “fgland-tubules. ]!ut in all fibres that are formed as e believes, from fused or coalesced cells (with the e-sceptions of those of the lens and enamel), the nuclei remain and undergo remarkable chan<res Espe! ‘‘I'i ‘It' nai-i-ow corpuscles, resemblino- fihie daik strne which he upon the exterior of the cell-fibres (that is, tlie fibres of Pells“'tn^theV ‘‘'.“’“‘^'''.ojPl'oses of cells, or which stand in the relation ot cells to the nuclei), in straight, angular, tortuous, or spiral lines. AfUr being thus changed they may be nearly absorbed; but more often they are further developed, and send out filaments by which they connect themselves into continuous fibres called nucleus-fibres, Henle describes two principal types according to which in these cases the nucleus.fibres are an-anged VYhen the cell-fibres are cylindriform, as those of he fibro-cellular tissue, they have the nuclei on their borders ; when they are flattened, as the organic muscular fibres, the nuclei lie on their flat surfaces In the former case the nuclei may lie in a row on one side only, and as t my elongate and are united, they form a band along one border of Bie fibre 01 they may he in rows alternately on two opposite sides, and each may jrrovv towards that on the opposite side which is at the next level above it fo as to form, when all have met, a spiral coil around the cell-fibre. In the latter case, that is, when the nuclei he on the surface of a flattened cell-fibre they have a tendency to send off lateral branches, and thus to connect themselves into^ a net-work over the surface of each layer of the fibres. The formation of the flattened fibres just spoken of is peculiar, and seems to be an example of a class of changes in development, which were not mentioned y Schwann ; those namely, vyhich are effected through the medium of a layer or sheet of structureless membrane. In the development of the coats of blood¬ vessels, for example, ayer after layer of cytoblastema in the form of struc¬ tureless membrane, is deposited ; and in each of these layers, nuclei are formed, w hich become the seats ot several different changes. Cells may form in the ordinary manner upon them, as in the development of the epithelium of blood- ^ reinain with little alteration, as in the inner membrane of n .vX ‘'i ''' fonnation of nucleus-fibres already described, they may elongate and arrange themselves in rows. In the last case, whicli occurs in the organic muscular fibres as well as in those of the contractile arterial coat, each row of nuclei appropriates, as it were, the adjacent strip of the