258 DISTRIBUTION OF NERVE-FIBRES, ETC. 



fibres of the frog were crossed at numerous points by 

 nerve-fibres, and that the nerve supply to each 

 elementary muscular fibre was much more free and 

 uniform than had been supposed. This fact was 

 demonstrated more especially in the thin muscles of 

 the eye and in the mylohyoid of the frog. 



281. Distribution of nerve fibres to the muscles of 

 the Hyla, or green-tree frog. Not satisfied with the 

 results of my investigations, published in 1862, I 

 examined numerous other muscles of the frog and 

 other animals, in the hope of being able to demon- 

 strate the finest nerve fibres in every part of their 

 course over the sarcolemma, but was not able to obtain 

 any muscle in the common frog so thin that I could 

 trace the finest branches over a very considerable 

 extent of surface. In the mylohyoid of the Hyla, 

 however, I found a muscle eminently adapted for this 

 investigation ; and on June 5th, 1863, I presented a 

 paper to the Royal Society upon the arrangement of 

 the nerves in this beautiful muscle. This memoir is 

 published in the " Proceedings." I have prepared 

 many specimens in which the nerve can be followed 

 from one undoubted nerve-trunk to another, dividing 

 and subdividing in its course, so as to form with 

 other nerves a lax network of compound nucleated 

 fibres, which compound fibres are often less than the 

 60000 of an inch in diameter. In PI. VIII, fig. 1, I 

 have given a sketch of this beautiful thin muscle, as 

 it appears when examined under a low magnifying 

 power. The vessels are injected. The nerve net- 

 work is well seen, as it ramifies over the two layers 

 of muscular fibres. The elementary muscular fibres 

 cross one another at right angles. 



282. The distribution of nerves to the muscles of 

 Articulata. The highly elaborate and rapid move- 

 ments of insects would lead to the inference that in 

 them the distribution of nerves to the muscles must 

 be very free. The textures are, however, so very 



