OF THE HUMAN BODY. 75 



regions; such is general anatomy; it imparts a knowledge of 

 the subject, a little more precise, than the more general view 

 above mentioned. But in order to know the human body, 

 in a positive and useful way, we must add to this, an exact 

 knowledge of each organ, in particular, and of each of its re- 

 gions; such is the object of special anatomy. 



General anatomy, considering together the organs similar as 

 to their texture, and confining itself to what may be generic or 

 common to them all, has for its special, but not its only object, 

 their texture. The special anatomy of the organs, improperly 

 styled descriptive anatomy, treats particularly of their con- 

 formation, for it is principally in this, that they differ from each 

 other; their respective situations, is the essential object of 

 topographical anatomy, or the anatomy of the regions. 



67. The external form of the human body, is symmetri- 

 trical;* it is divided into two lateral similar halves, by a me- 

 dian verticle line. This line is even marked, in some places, 

 where it forms what are called raphae or seams, which, in 

 fact, appears to result from a sort of sewing, or junction of 

 the two lateral portions, originally separated. This symme- 

 try is not equally perfect in all parts of the body; it is more 

 so in the organs of animal functions, and less so in those of the 

 vegetative functions, particularly in those of nutrition. In 

 fact, the bones, the nervous system, the senses, and the mus- 

 cles, are the most symmetrical parts, while the organs of di- 

 gestion, of circulation, and of respiration, are less so than the 

 genital organs. It would not be exactly correct, however, 

 to say that symmetry belongs to the former, and is foreign to 

 the latter ; it belongs, generally, more to the external parts, 

 and is less perfect in those that are deeply seated; thus the 

 lachrymal and salivary glands, the thyroid gland, the mammae, 

 the testicles, and all the organs of the functions of nutrition and 

 generation, are symmetrical; while the nerves of the*larynx, 

 of the stomach, of the intestines, and the diaphragm, are not. 

 It is also to be observed, that certain parts, which are develop- 

 ed at a later period are less symmetrical than those of the 



* See, among others, Bichat, Reck. Physiol sur la vie and la mort- 

 Meckel, Beitz. zur vergl. anat. Leipz. 1812. 



