A lecture introductory to the course of anatomy and physiology, delivered in the Medical School, Aldersgate Street, London, upon the opening of the session, 1832 / by Robert Bentley Todd.

  • Todd, Robert Bentley, 1809-1860.
Date:
1832
Catalogue details

Licence: Public Domain Mark

Credit: A lecture introductory to the course of anatomy and physiology, delivered in the Medical School, Aldersgate Street, London, upon the opening of the session, 1832 / by Robert Bentley Todd. 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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    it were, people the waters, and which are found in all the countries of the world, under certain circumstances. From the fact that these beings are invariably found in fluids, sea and fresh water, and the infusions of various animal and ve- getable substances, they have been designated mfusory animalcules. It is not, however, to be supposed that all in- fusory animalcules are of such extreme simplicity of organiza- tion; many of them are much more complicated, some pos- sessing an outer shell, others provided with tentacula or arms, and others exhibiting a regular apparatus of stomach and intestines. On the minute structure of these animalcules the recent observations of Ehrenberg have thrown much light. It is, however, as the inhabitants of infusions that we meet those simplest forms of existence with which we commence the scale: the volvox and the monas are those to wh ich I more especi- ally allude, and with which every microscopic observer is familiar. The earliest animals have received from zoologists the appel- lation zoophyte, signifying animal-plant; a name applied to them in consequence of an imaginary, gradual, or almost insensible transition from plant to animal. The term protozoa adopted by Goldfuss would be more scientific, as involving no theory. This genus, you observe, heads the scale which I have constructed. The first complication which is made in these simple animal points, as they have been called, consists in the addition to the exterior of the animal of delicate processes extending from its body; some of which are so minute as to present the appearance of hairs; others are longer and more distinct in character, and resemble, on a very small scale, the feelers and tentacula of the more advanced animals. But the most im- portant addition or alteration is that which has taken place in the interior of the animal. It can no longer be described as a solid globule of animal matter; its body now begins to be hollowed out, and soon a regular cavity is formed in it, so that it would appear to be little more than a stomach provided with arms for taking its prey. Such is the general descrip- tion of a class of animals with which every one is familiar by name, I mean the polypes; they are defined by Lamarck as gelatinous animals with elongate! ^ontractile body, having