28 Dr. Anderson on the Physiologr/ of Cells. 



9th February J 1842, — TJie President in the Chair. 



IX On the Physiology of Cells. By Andrew Anderson, M.D. 

 Andersonian Professor of the Institutes of Medicine. 



A SKETCH was given of what has been called the " Theory of Cells," 

 in physiology, based on the observations of Schwann, Schleiden, Barry, 

 and others. 



It was shown that it has now been rendered probable, that not only 

 every tissue of every plant and animal, but the secretions and other 

 products of organized beings, are formed in one way, by the sponta- 

 neous evolution of transparent vesicles, or cells full of fluid, and con- 

 taining the germs of future cells, which are subsequently formed within 

 them ; that these cells possess a power of absorption, by which they 

 increase by the appropriation of matter from without ; of transforma- 

 tion, both in respect of their own form, and of these absorbed materials ; 

 and that it is by the living power of the cells that the nutrition and 

 reproduction of the tissues goes on, and, in short, that all the changes 

 are effected, by which we recognize the presence of life. 



That the beauty and simplicity of this theory are unsurpassed, and 

 that while it seems to have marked a new era in physiology, the evi- 

 dence in its favour is such as almost to make it rank among the estab- 

 lished facts of the science. 



[Specimens, drawings, and diagrams were then exhibited, to explain 

 and demonstrate the structure and growth of cells, and the formation 

 of tissues from them.] 



The subject of reproduction was next alluded to, and it was shown, 

 that while the lowest organized beings, as the yeast-plant, consist but 

 of a single cell, by the multiplication of which they increase and are 

 propagated, — so we conclude, that while in them the simplest expres- 

 sion of a living being is a cell, the same holds true with respect to the 

 higher ranks of plants and animals, and even man himself. That the 

 embryo is formed ^by the union of two simple cells, which include 

 within them, not actuaily, but potentially, the future being; that is, 

 which have within themselves a living energy, capable of successively 

 forming the parts of such a being, from the nutritive materials ab- 

 sorbed from without ; and thus, that organized life — that which man 

 possesses in common with plants, is identical with the powers of the 

 microscopic elementary cells of which his body consists. 



Lastly, a few remarks were made to show the bearing of this theory 

 on pathology ; how it is that many diseases may arise from a perverted 

 state of the vital action of cells ; how others, as the porrigo, evidently 

 depend on the formation of abnormal cells, putting on the aspect of 

 organized beings of the lowest class; and the paper concluded by 

 general remarks on the extreme interest and the practical impor- 

 tance of the subject. 



