516 



NERVOUS SYSTEM. 



or knotted coils. The nerve-fibres are medullated for a certain distance, 

 but their terminations are generally pale. The above is one form of these 

 corpuscles. Sometimes, however, the terminal bulbs 

 are oblong, and sometimes but a single nerve-fibre 

 penetrates the bulb and terminates in a simple, pale 

 filament. The principal forms of the terminal bulbs 

 are shown in Fig. 181. 



General Mode of Termination of the Sensory 

 Nerves. The actual termination of the sensory 

 nerves upon the general surface and in mucous 

 membranes is still a question of some obscurity. 

 Although anatomists have arrived at a pretty definite 

 knowledge of the sensory corpuscles, it must be 

 remembered that there is an immense cutaneous and 

 mucous surface in which no corpuscles have as yet 

 been demonstrated ; and it is in these parts, endowed 

 with what may be called general sensibility, as dis- 

 tinguished from the sense of touch, that the mode 

 of termination of the nerves remains to be studied. 



According to Kolliker, in the immense majority 

 of instances the sensory nerves terminate in some 

 way in the hair-follicles. If this be true, it will 

 account for the termination of the nerves in by far 

 the greatest portion of the skin, as there are few 

 parts in which hair-follicles do not exist ; but un- 

 fortunately the exact mode of connection of the 

 nerves with these follicles is not apparent. The 

 following seems to be all that is positively known 

 FIG. m.-End-buibs. or cow*- of the terminations of the nerves on the general sur- 



cles of Krause (Ludden). face I 

 A, three corpuscles of Krause -nr i 11 i_ -i .m i J.T 



from the conjunctiva of Medullated nerve-fibres form a plexus in the 

 acid'; magSfieiFsoo diam deeper layers of the true skin, and from this plex- 

 sr 



two nerve-fibres us, fibres, some pale and nucleated and others me- 

 terio^p^rtio^sof'two'p^ dullated, pass to the hair-follicles, divide into 

 branches, penetrate into their interior and are there 

 lost. A certain number of fibres pass to the non- 

 striated muscular fibres of the skin. A certain 



m tS^hre^corpuscies, the number pass to papillae and terminate in tactile cor- 



pusclesi and others pass to papilla? that have no tac- 



B, terminal bulbs from the con- -Hlo nrT*rmarlcKa 

 junctiva 9 f the calf, treated T 0-rpUSCieS. 



id; In t^e mucous membranes the mode of termina- 



tion is ' in g eneral terms, by a delicate plexus just 

 of a 'nerve-fibre, with two beneath the epithelium, coming from a submucous 



terminal bulbs ; a, covering 



of the terminal bulbs; 6, in- plexus analogous to the deep cutaneous plexus. In 



ternal bulb ; c, pale nerve- r . r . , 



fibre. certain membranes the nerves terminate in end- 



bulbs, or corpuscles of Krause. In the cornea, according to the observations 



