492 GENERAL ANATOMY. 



general as they approach their termination; they become flat, 

 and are then no longer visible while it appears that they should 

 still be so. There exists two hypotheses upon the final ter- 

 mination of the nerves: one is not perhaps better founded 

 than the other. According to one of these hypotheses, the 

 nerves lose themselves, so to speak, in the organs, identifying 

 themselves with their substance, which is imbibed with them, 

 if we may use the expression. According to the other, which 

 belongs to Reil, the nerve, not being capable of expanding 

 throughout every organ at once, is surrounded with a nervous 

 atmosphere in which it extends its action, nearly as is seen in 

 electric phenomena. What has led to these hypotheses, is 

 this remark, that the nerves expand into parts the extent of 

 which is much greater than their own, even after they are di- 

 vided as far as the eye, armed with a microscope, can follow 

 them, as is seen in the muscles, the skin,, the senses, and that 

 notwithstanding each point of these parts, however small it 

 may be, presents, when it is punctured, the same phenomena 

 as when the nerve itself is punctured. 



The different parts do not receive an equal number of nerves. 

 The organs of sense are those which contain the most: the eye 

 and the ear, present membranous expansions entirely formed 

 of nervous substance. The skin, particularly at the hands 

 and the lips; the mucous membranes, as well on the exterior 

 as the interior; the glans and the different parts of the vulva, 

 placed at the point of junction of these membranes with the 

 skin, receive most nerves after the principal organs of the 

 senses. Then come the exterior muscles, afterwards the in- 

 terior, the blood vessels, among which the arteries receive 

 more than the veins, or the lymphatic vessels in which their 

 existence is not certain. The existence of the nerves is doubt- 

 ful in the other parts, or in those which have cellular fibre 

 for their basis, if the vessels are excepted, as the cellular tis- 

 sue, the serous and synovial membranes, the cartilages, the 

 bones, &c. : these parts, in fact, do not appear to receive nerves. 

 Finally the corneous parts and the epidermis are certainly 

 deprived of them. It is possible, on the contrary, that they 

 exist in the preceding tissues, and that their softness or their 



