On the structure and development of the liver / by C. Handfield Jones ; [communicated by Sir Benjamin Collins Brodie].

  • Charles Handfield Jones
Date:
1849
Catalogue details

Licence: Public Domain Mark

Credit: On the structure and development of the liver / by C. Handfield Jones ; [communicated by Sir Benjamin Collins Brodie]. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    as the homologue of the hepatic apparatus we have just examined, I will enter on a rather more particular account of it, which will disclose I think some characters illustrative of hepatic structure in general. It may be described as consisting of two portions, one in which the constituent cells are free, entirely separate from each other, or only fused together in very small groups, and another in which the cells are com- pletely fused together so as to represent either simple undilated tubes, or tubes irre- gularly constricted and bulged at intervals ; the former is evidently that part of the organ where the production of fresh cells takes place; these are seen at first as granular cells with envelopes more or less distinct, but having only imperfect traces of nuclei; subsequently the characteristic biliary spherules appear in them, and at last fill them completely. Now the cells becoming developed in this manner (and they proceed exactly in a similar manner in the Earthworm) may either become fused together to constitute the tubes above described, or they may lose all trace of an en- veloping membrane ; their component spherules separating from each other, and the cell at last undergoing complete disintegration on the spot where it had been originally formed, while its elaborated contents are probably absorbed into the circulating stream, from whence as plasma they had proceeded. The contents of the tubes are doubtless poured into the intestine, while the debris of the free parenchymal cells are scattered throughout the surrounding tissue, and thus in this low Annelide we seem to recognise a division of the hepatic apparatus into two portions, similar to those which we shall shortly distinguish in the higher animals ; these have probably separate functions, the tubular influencing by its secretion the intestine and its con- tents, while the parenchymal seems adapted to supply material direcfly for the use of the respiratory process. In the Arenicola, the biliary cells are of a lighter colour than in the Leech or Earthworm ; they are at first of a pale granular aspect and often exhibit nuclei; subsequently they acquire dark oily-looking contents, and often change their form, becoming remarkably elongated ; their diameter varies from two to °f an inch. If the outer surface of the intestine be examined with a low power, it is found to present the convexities of numerous short sacculi with intervening furrows, and to be perfectly even and defined, while the inner surface, on the contrary, has a floccu- lent, almost ragged appearance. This effect is due to the disposition of the cells, which form a moderately thick stratum, resting on an homogeneous membrane, the sole constituent of the intestinal wall; the cells are therefore actually in the cavity of the intestine, and in immediate contact with its contents ; they contrast herein remarkably with those of the Earthworm, which we have seen to lie on the outside, for the cells of the Sandvvorm may be completely removed by washing the inner surface of the intestine, while those of the Earthworm can be thus detached only from the exterior. These three instances from among the Annelides seem to exhibit the extreme varieties pf condition which the hepatic apparatus is capable of assuming. In the Earthworm
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