2153. In the heart the flexor layers have not yet separated from the extensor layers, because the vegetable flesh has as yet no symmetry in itself. 2154. Flexors and extensors occur in pairs; because the osseous system is in pairs. 2155. There resides in the osseous and in the muscular system no cause for a diversity in the two halves of the body. Thus, if there be a difference, it must only reside in the asymmetrical galvanic systems. 3. _Organs._ 2156. Organs are parts of an anatomical system, which separating, combine with a part of another system, and thereby obtain a peculiar or special function. 2157. For each system therefore there are as many organs, as there are possible combinations of systems. There are vascular, intestinal, pulmonary, sexual and tegumentary organs, with furthermore, osseous, muscular and nervous organs. A. VEGETATIVE ORGANS. 1. INTESTINAL ORGANS. 2158. The intestinal or splanchnic system falls first of all into three great divisions, into that of the viscera, the sex and the head; the visceral intestine separates moreover into pulmonic, venous and tegumentary intestine, and this in constant accordance with its combinations and functions. a. _Visceral Intestine._ 2159. In the digestive system it is the chemical process that takes precedence. This, however, divides into three moments, into that of _solution_, _separation_ and _formation_, or crystallization, which is here _absorption_. Thus the intestine separates also into a solvent, secernent and absorbent intestine, and that indeed through its combination with the pulmonic, vascular and tegumentary system. The solvent viscus is the stomach, the second or secernent, the duodenum, the third or absorbent, the small intestine (jejunum and ileum). _Pulmonic Intestine._ 2160. All solution is accompanied by oxydation. The gastric juice is in its action an acid. 2161. The gastric juice obtains its oxygen from the spleen. The spleen is the stomachic lung. This is attested by its position and close approximation to the stomach; by its black, venous, and deoxydized blood, which in certain diseases has been secreted even in the stomach; by its want of any excretory duct; by its tissue, which resembles that of the oxydized placenta; furthermore by the natural character of this function when contrasted with the unnatural quality of other useless functions that have been assigned to it; and lastly too, by the fact that, without this opinion be admitted, it must remain a superfluous organ, and as regards use, unknown. After a series of years, during which this doctrine has been combated upon all sides, without, however, a single reason, save and except that it was not believed, being advanced by its opponents, I must still persist in the correctness of the above view. _Vascular Intestine._ 2162. In the duodenum the _analysis_ of the food takes place through the medium of the bile. It is consequently the _biliary_ intestine or stomach.