MUSCLE AND TENDON (nkEVE-ENDINGS). 339 



by injection through the internal carotid. For elastic 

 fibi-es, Weigert's resorcin-fuchsin, followed by 1 per cent, 

 orcein acidified with HCl. 



Electric Organs. 



673. Electric Organs. — Ranvieb [Traiti', Chap, xviii), finda 

 that osmic acid is the only reagent that will fix properly the 

 terminal arborisations on the lamellaE!. He injects a little 

 2 per cent, solution under the surface of the organ^ removes 

 a small portion of it after a few minutes, and puts it into a 

 quantity of the same solution for twenty-four hours. The 

 electric plates may then be teased out and examined in 

 water, and will show tlie stag's horn ramifications; and the 

 dissepiments between the columns will show the bouquets of 

 Wagner. The terminal arborescence may be impregnated 

 with silver. A portion of the surface of the organ is 

 rubbed with lunar caustic until it appears opaque, then 

 removed and the plates teased out in water. This gives 

 negative images. 



Or, electric plates, isolated by teasing after twenty-four 

 hours in osmic acid as above, and kept for some days in 

 one-third alcohol, are washed and placed on a slide with 

 their ventral surface uppermost. They are then treated with 

 a few drops of 0'5 per cent, solution of chloride of gold 

 and potassium, and those which become violet are washed 

 and mounted in glycerin. This gives positive images. 



These may also be obtained by putting material fixed by 

 osmic acid into 2 per cent, solution of bichromate of 

 ammonia for a few weeks, then teasing, staining with alum 

 hsematoxylin, and mounting in damar. 



Torpedo. — Ballowitz (Arch. mik. Anat., xlii, 1893, p. 460) 

 gets the best results by the rapid Golgi impregnation. 



An electric column, with about -I- to 1 cm. of tissue 

 round it, is dissected out, and put for three to four days 

 into the osmium bichromate mixture ; then for one to three 

 days into -f- per cent, silver, cut without imbedding and 

 mounted in xylol balsam. Impregnates all the important 

 elements. See further, on the whole subject, Ballowitz, 

 Encycl. mik. Techn., 1910, p. 298. 



Cavalib [Bill. Anat., xiii, 1904, p. 214) takes material 



