DISTRIBUTION OF NON-MEDULLATED NERVE-FIBRES. 123 



The formation commences in the interior of the cellular cap- 

 sules of the cartilage, and then extends also into the funda- 

 mental intercapsular substance. 



All these calcareous formations become charged also with 

 organic colouring matters, whether naturally contained in 

 the liquid or purposely dissolved in it. Not only colours of 

 animal origin, but also those from vegetable sources, such as 

 saffron, turnsole, logwood, &c., are absorbed, so that the 

 coloured calcareous formations met with in animals may thus 

 be reproduced. 



On the Peripheral Distribution of Non-medullated 

 Nerve-fibres. By Dr. E. Klein. (With Plate IX.) 



Part III. 



In the second part of this memoir we have described, 

 among other subjects, the distribution of fine non-medullatcd 

 nerve-fibres on the capillaries of the nictitating membrane 

 as well as of the mesentery of the fi;og. 



We there saAv how from the large non-medullated nerve- 

 fibres still provided with a nucleated sheath, which accom- 

 pany the vessel for a longer or a shorter distance, finer 

 nerve-fibres spring off and join to form a plexus round the 

 capillary vessel ; further, we were able to follow from thib 

 plexus still finer nerve-fibres Avhich partly run in the Avail of 

 the vessel itself, in which wall they divide and join by their 

 lateral branches so as to form a network. 



What I am going to treat of in this third part will con- 

 cern first the relation of the non-medullated nerve-fibres to 

 small arteries, small veins, and to capillary vessels, in the 

 muscular substance of the frog's tongue; and secondly, the 

 termination of nerve-fibres in the already mentioned ciliated 

 duct in the tail of the rabbit. 



A. Nerves of the Blood-vessels in the Frog's Tongue. 



The preparations figured in PI. IX, figs. 1, 2, and o, were 

 obtained by the following process : — The whole tongue of the 

 living frog is cut out. It is then pinned out on a piece of 

 flat cork, from which it is raised slightly like a tent so as 

 completely to remove its lower surface from the cork, and 

 immersed in half per cent, solution of chloride of gold for 



