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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    even a gnat light upon one of the glandular organs which are attached to them? Again, is it not in obedience to the stimulus of the sun’s rays, that the Iieliantkus or Sunflower has its blossom always directed towards the sun? Time would fail me, were I to enter upon a refutation of this objection: it will suffice to state, that the phenomena attri- buted to the so called sensibility or irritability of plants, are the necessary effects of mechanical causes, or dependent on a power, in many respects, dissimilar to animal irritability.* If we then modify the Linnsean aphorism, and while we assign to plants the properties of life and growth, give to animals those of life, growth, and irritability, we shall have a more precise line of demarcation between the two classes of beings. In addition to irritability, animals have certain essential characters serving still more to distingish them from vegeta- bles. They are the only living bodies capable of action and of moving themselves from one place to another; their motions take place frequently without any cognizable cause; they introduce their food into their bodies of themselves, and it is one of their functions to assimilate portions of it, reject- ing those parts which are not adapted for nutrition. The contrast with vegetables is sufficiently obvious; fixed to the soil by their roots, they draw from thence their nutritious fluids which require no elaboration within them; they, there- fore, do not require and do not possess the power of loco- motion, nor have they any internal principle to stimulate them to action. Many atttempts have been made to account for the pheno- mena of living beings, but what more can be said upon the subject than that they are phenomena only co-existent with life. Of the essence of life we are utterly ignorant; we know it only as the connecting bond which unites and keeps in action a certain assemblage of f unctions in an organized body. I would strenuously caution you against the danger of forming * Those who desire to investigate this subject further, I refer to Lamarck’s Histoire Naturelle des Animaux sans Vertebres, tom. i. Introduction.