The discovery of the nature of the spleen : from an investigation of the lateral homologies of the liver, stomach, and intestinal canal / by Henry R. Silvester.

  • Silvester, Henry R. (Henry Robert), 1829-1908.
Date:
1870
Catalogue details

Licence: Public Domain Mark

Credit: The discovery of the nature of the spleen : from an investigation of the lateral homologies of the liver, stomach, and intestinal canal / by Henry R. Silvester. 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.

    46/64 (page 46)
    4G the cellular tissue of the lung, forming plexuses in the in- tei'lobular cellular tissue, and spreading out upon the surface of tlie lung beneath the pleui'a, may be compared with the hepatic arteries, and the pulmonary vessels which convey the blood sent through the lung by the heart for aeration may be compared with the portal vein. Without going at great length into the comparative anatomy of the lung, we may note that in fishes the air- bladder formed by a prolongation of the internal tegumen- tary membrane constitutes a rudimentary lung, and exists at the same time that the lung-function is being performed by the gills. The air-bladder is, in fact, acknowledged to be an accessory I'espiratory organ. In some fishes the resem- blance of the air-bladder to a lung is very decided, and its connection with the function of i-espiration is evidently most important. The canal by which it communicates with the alimentary canal opens, in some instances, at the back of the mouth; so that a gradual approach is seen to the ar- rangement which exists in air-bi'eathiug animals. In these fishes, as in the amphibia that retain their gills, it would appear that the respiration is accomplished partlj^ by the lungs, and jiartly by the gills. Tliere can be no doubt that the lung may be regarded as a combination of the air-blad- der and the gills, and that however perfectly the union is accomplished, it is in reality a combination of two dis- tinct organs, and there are not indeed wanting indications in the mammalian lung of the combined function of the two organs of whicli it was originally composed. With regard to the liver, the evidence is more conclusive ; for the function of each portion can be readily detected, not- withstanding that, as in the case of the lung, the structui-al union is complete. From time to time, various attempts have been made to separate, anatomically, the substance of the liver into two distinct portions, and this in consequence of two dis- tinct functions of the liver having been recognized by many physiologists. Ferrein went so far as to describe the medullary sub- stance as being red in colour and of a pulpy consistence, and the cortical as friable in its structure and of a yellow- ish red colour; and Miiller distinctly admits a kind of double substance, although he objects to its designation, medullary and cortical. In his pliysiology, however, he