Observations on certain parts of the animal oeconomy : inclusive of several papers from the Philosophical transactions, etc. / by John Hunter ... ; with notes by Richard Owen.
- John Hunter
- Date:
- 1840
Licence: Public Domain Mark
Credit: Observations on certain parts of the animal oeconomy : inclusive of several papers from the Philosophical transactions, etc. / by John Hunter ... ; with notes by Richard Owen. Source: Wellcome Collection.
Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)
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![of the external oblique muscle ; but the orifice and upper end of the sac would not by any means admit of the testis being passed quite up into the abdomen. However this may be, the upper end of the sac certainly contracts and unites first, and is quite closed in a very short space of time, for it is seldom that any aperture remains in a child born at its full time; and this contraction and union is con- tinued downwards till it comes near the testicle, where this disposi- tion does not exist, leaving the lower part of the sac open or loose through life even in the human subject, and forming the tunica testis vaginalis propria, the common seat of a hydrocele. Many cases of hydrocele in children seem to prove that the progress of this contraction and union is downwards; for in them the water commonly extends higher up the chord than in the adult, except in those of a considerable size; yet in some children this union seems not to take place regularly, being interrupted in the middle, and producing a hydrocele of the chord which neither communicates with the abdomen nor tunica vaginalis testis. The contraction and obliteration of the passage appears to be a peculiar operation of Nature, depending upon steady and uniform principles, and not the consequence of inflammation nor of anything that is accidental; and therefore, if it is not accomplished at the proper time, the diffi- culty of bringing about a union of the parts is much greater, as is seen in children who have had the sac kept open by a turn of the intestine falling down in the scrotum immediately after the testis. This looks as if Nature, from being balked when she was in the humour to do her work, would not or could not so easily do it afterwards. I shall readily grant that what has been advanced here as a proof of the doctrine may be explained upon other principles; but this at least is certain, that the closing of the mouth and of the neck of the sac is peculiar to the human species ;* and we must suppose the final intention to be the prevention of ruptures, to which men are so much more liable than beasts from their erect state of body. In some cases the aperture of the sac is not entirely closed, allow- ing a fluid to pass down and form a hydrocele ; which fluid, upon pressure, can be squeezed back into the belly ; and instances of this kind sometimes giving the idea of a gut being protruded, make it difficult to determine the exact nature of the case. What is the immediate cause of the descent of the testis from * [The chimpanzee, or African orang-utan (Simia Troglodytes, Blum.), which of all mammalia approximates most closely to the human structure, resembles man in the early obliterations of the canal which leads from the peritoneal cavity to the tunica vaginalis. In the Indian orang (Simia Sal'yrus, Linn.), on the con- trary, the canal of communication is free. This difference of structure relates doubtless to the different conditions of the lower extremities in these otherwise closely allied quadrumana: in the chimpanzee they are proportionally larger and stronger, the leg can be more extended on the thigh, and the hip-joint is strength- ened by a ligamentum teres; in the orang, on the contrary, the lower limbs are freely developed as organs of support, but have great extent of motion, the hip- joint being, like the shoulder-joint, without a round ligament.]](https://iiif.wellcomecollection.org/image/b21131545_0017.jp2/full/800%2C/0/default.jpg)
