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.

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    place of junction is, however, frequently indicated by the presence of a csecum, or rather of two cseca, for this diver- ticulum is most commonly double. The cseca ai'e wanting in some vultures; in the cormorant, wryneck, and toucan, and in many carnivorous, insectivorous, and fragivorous bii-ds. They are small and short in other vultures, in the eagles, and solan goose, and also when they exist in the insessorial tribes; they are longer in the nocturnal than in the diurnal birds of prey. Among the rasores, they are short in pigeons, but very long in the grouse, each measuring three feet, or thrice the length of the body. In other rasores they are of moderate length. In the cursorial birds the intestinal canal approaches more nearly the mammalian character. The cseca, however, are absent in the cassowary, whilst in the ostrich they are wide, about two feet long, and have an internal spiral fold, like that of the hare. The large intestine beyond the cseca is large and mammalia-like in the ostrich, but usually is relatively short, straight, and not very wide. It terminates by an imperfect valved circular opening in the dilated cavity called the cloaca, into which also the ureters and the ducts of the reproductive organs open. In Reptiles.—The pyloric valve is usually present in reptiles, though not very distinct; the intestine is shorter and wider than in birds. In saurians there is mostly an ileo-colic valve; the crocodile has no cajcum. In the chelonians the intestine is long and muscular; an ileo- caical valve usually exists, and also frequently a csecum. In serpents the small intestine is elongated, the ileo-colic valve is indistinct, the large intestine sometimes has transverse folds in its interior analogous with the spiral valve in the same part in the cartilaginous fishes. The lower end of the larger intestine forms a cloaca, receiving the ducts of the urinary and reproductive organs. The presence of a caicum in certain chelonia is associated with the use of a vegetable diet. In the more fish-hke batra- chians the division into small and large intestine is imper- ceptible ; the latter ends in a cloaca. In FisJies. —The intestine is short and wide, and is distinguished into a large and small intestine by a slight constriction only; there is no distinct ileo-colic valve, but sometimes a short cajcum exists. The small intestine has usually connected