Volume 1

Biennial retrospect of medicine, surgery and their allied sciences, 1865-74 / edited by Henry Power ... [and others].

Date:
1867-75
Catalogue details

Licence: Public Domain Mark

Credit: Biennial retrospect of medicine, surgery and their allied sciences, 1865-74 / edited by Henry Power ... [and others]. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    14/546 (page 4)
    as the lymphatics of these parts, partly on account of their form, size, and mode of brandling, and partly because they can be directly injected from the lymphatics of the pia mater. Other microscopists, however, as I'rommann, attribute the appearances in question to retraction of the tissues, consequent on the mode of preparation. His believes that the perivascular spaces act both as reservoirs for the nutritious fluids and also serve as a means of protection for these important parts against pressure, serving the same purpose for each individual segment of the nervous system that the liquor cerebro-spinalis does for the whole organ. When a solution of nitrate of silver is injected into the lymphatics the parietes of the smaller vessels are found to present certain wavy dark lines. Two explanations have been given of the cause of this appearance ; V. Recklinghausen refers it to the staining of the tissues intervening between the epithelial cells and connecting them together; whilst Auer- bach (Researches on Lymph and Blood-vessels, 'Virchow's Archiv,' Bd. 33, p. 340) thinks it due to the combination of the silver salt with thread-like masses of albuminous and saline materials lying in fissures of the vessels. The lines vary in breadth, and this appears referable, in part at least, to the strength of the silver solution. S. Basch ('Wiener Sitzb.,' Bel. 41), who has paid particular attention to the commencement of the lacteals in the villi, regards these vessels, in opposition to Teichmann and others, as only large and regular-formed spaces, possessing neither a proper wall nor an epithelial lining, the illusory appearance of the latter being due to the presence of lymph- corpuscle-like bodies, belonging to and forming part of the proper connective tissue of the villus. Great discrepancy of opinion, it is well known, exists as to the mode in which oleaginous and other constituents of our food gain entrance into the lacteals, some admitting with Heidenhain that the cells which cover the intestinal surface of the villi present open mouths at their free extremities, and possess caudate processes at their attached ends, which are prolonged into the tissue of the villus, and either enter into direct continuity -with the central lacteal or are indirectly continuous with it through the con- nective-tissue-corpuscles, in either case a system of canals and passages being formed, through which fine particles of any foreign body may easily enter; whilst others hold that the cells of the villi are certainly closed, that all absorption is effected by true osmosis or through the exquisitely fine pores of the membranous structures, and that when particles of solid or fluid matter have been observed to gain entrance into the lacteals it has been in consequence of mechanical lesion of the mucous membrane. Some interesting observations have recently been made by L. Letzerich ('Virchow's Archiv,' ] 866, Bd. 37, Heft a), which, if corroborated by other observers, will serve to elucidate the process of absorption of fat, and to explain the conflicting statements that have been made. He believes that he has been able to distinguish two kinds of cells on the surface of the villi. One of these is the ordinary columnar epithelial cell, with closed extremities ; whilst the other consists of a spherical, pear-, or spindle-like body, the free extremity of which, turned towards the intes- tine, is wide open, whilst the other or attached end is tapering, penetrates the basement membrane, and discharges its contents into a kind of plexus,