Connective Tissue, Nerve, and Muscle. 531 



Fig. 14. Elastic fibres with cells. Section from gold preparation of skin of adult 

 rabbit treated by concentrated acetic acid. 3. VIII. Tube out. 



Fig. 15. Fibres from the ligamentum nuchae of a three-days-old foal. Gold prepara- 

 tion. The nuclei and remains of the protoplasm of the cell stained. 3. VIII. 

 Tube out. 



Fig. 16. Ligamentum nuchae of three-days-old foal stained in gold and hasmatoxylin. 

 The central canal of the fibres indicated by the haematoxylin. 3. VIII. 

 Tube out. 



Fig. 17. Fibre from the same preparation as fig. 15. XII. Tube out. 



Fig. 18. Cells from the fibres of the sciatic nerve of the -/6g. Isolated by the saturated 

 solution of potash. 3. VII. Tube out. 



Fig. 19. Nerve-fibre from the sciatic nerve of the mouse. Treated by absolute alcohol, 

 dyed with hrematoxylin, and the excess of colour removed by acetic acid. 

 3. VIII. Tube out. 



PLATE XI. 



Fig. 20. Perimysium of a muscular fibre of frog stained in haematoxylin. Flat cells 

 seen. 3. VII. Tube out. 



Fig. 21. Muscle of mouse subjected to prolonged action of warm potash solution. The 

 cells on the sarcolemma indicated. 3. VIII. Tube out. 



Fig. 22. Flat cells from the sarcolemma of muscular fibre of ox. Isolated by pro- 

 longed action of warm potash solution. 3. VIII. Tube out. 



Fig. 23. Muscular fibre of mouse treated by solution of potash. The holes in the sar- 

 colemma seen. 3. VIII. Tube out. 



Fig. 24. Muscular fibre of frog treated by solution of potash. Canals indicated by 

 nuclear vacuoles. 3. VIII. Tube out. 



Fig. 25. Muscular fibre of frog. Gold preparation. Sarcolemma rent longitudinally 

 and flattened. Septa dividing muscular substance visible. 3. VII. Tube 

 out. 



Fig. 26. End view of muscular fibre of frog. Gold preparation. Stellate s ->aces with 

 nuclei and processes of branched cells, having the signification of elastic 

 fibres, between the bundles. 3. VII. Tube out. 



Fig. 27. Muscular fibre of frog. Gold preparation. The fibrillae separated by teasing 

 into bundles, between which long narrow flat cells are seen. 3. VII. Tube out. 



Fig. 28. Muscular fibre of frog. Gold preparation. The central cavity seen much 

 enlarged by the astringent action of the gold. 3. VII. Tube out. 



" On the Refraction of Sound by the Atmosphere." By Prof. 

 OSBORNE REYNOLDS. Communicated by Prof. G. Gr. STOKES, 

 Sec.R.S. Received March 18, 1874*. 



My object in this paper is to offer explanations of some of the more 

 common phenomena of the transmission of sound, and to describe the 

 results of experiments in support of these explanations. The first part 

 of the paper is devoted to the action of wind upon sound. In this part of 

 the subject I find that I have been preceded by Professor Stokes, who 

 in 1857 gave precisely the same explanation as that which occurred to 

 me. I have, however, succeeded in placing the truth of this explanation 

 upon an experimental basis ; and this, together with the fact that my 

 work upon this part of the subject is the cause and foundation of what 



* Eead April 23, 1874. See ante, p. 295. 

 YOL. XXII. 2 S 



