238 DISTRIBUTION OF NERVES, ETC., IN BLADDER OP FEOG. 



sion and subdivision of dark-bordered fibres. But 

 vpbetlier tbe large dark-bordered fibres seen in tbe 

 nerve-trunks pass directly to tlieir distribution in the 

 bladder, or in the first place become connected with 

 ganglion-cells, it is difficult to decide with, absolute 

 certainty; I have, however, traced several of the 

 large dark-bordered fibres directly from the trunks to 

 their distribution, but even in these instances I am 

 not prepared to assert that no branches pass to the 

 ganglion- cells. My impression is that many of the 

 fibres do so, but that some pass to their distribution 

 vdthout being connected with ganglion-cells. I think 

 it probable that, of the fibres resulting from the 

 division of a dark-bordered fibre derived from the 

 spinal cord, some may become connected with the 

 ganglion- cells above referred to, while others pass to 

 their distribution in the bladder without being con- 

 nected with these cells. 



In the very thin membrane of which the walls of 

 the frog's bladder are composed we may follow out 

 the distribution of nerves — a, to the muscular tissue, 

 6, to the sui'face of the mucous membrane, c, to the \ 



vessels, and d, to the connective tissue. There is a 

 network ramifying on the outer surface, from which 

 fibres pass to supply all the tissues of the bladder. 



The muscular fibre-cells of the bladder itself and 

 of the small arteries are crossed sometimes in two or 

 three places by veiy fine nerve-fibres ; and not un- 

 f requently the nerve- fibre runs parallel with the mus- 

 cular fibre-cell for some distance. Fig. 1, PL V, p. 21.7. 



Some of the most recent drawings of this form of 

 muscular tissue and the supposed arrangement of its 

 nerves are very defective. J. Arnold, in his article on 

 organic muscle in Strieker's "Anatomy," has given 

 some not very satisfactory drawings of the muscular 

 tissue from the frog's bladder. His figm'es on page 

 142, are evidently taken from himdles of muscular 

 fibres. The delicate cells, isolated ready for obser- 



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