352 MUSCLE AND TENDON. 



ment with formic acid being omitted, and the muscles being put 

 for a couple of days into glycerin after reduction in the acid. 



The procedure of TRINCHESE (Mem. R. Accad. 1st. Bologna, 

 5, ii, p. 279; Zeit.f. wiss. Mik., ix, 2, 1892, p. 238) is also 

 practically identical. 



RANVIER (Traite, p. 813) finds that for the study of the 

 motor terminations of Batrachia the best method is his lemon- 

 juice and gold-chloride process ( 226). The delicate elements 

 of the arborescence of Kiihne are better preserved by this 

 method than by the simple method of Lowit. 



For the study of the motor plates of reptiles, fishes, birds, 

 and mammals, he finds (ibid., p. 826) that his formic acid and 

 gold- chloride method, 225, gives preparations infinitely 

 superior to those obtainable by the method of Lowit ; but the 

 lemon-juice method is still better, especially for lizards and 

 mammals. The branches of the terminal arborescence are 

 more regular than in preparations obtained by the formic 

 acid process. 



668. Nerve-endings the Silver Method. RANVIER finds that 

 the silver nitrate method of Cohnheim is also useful. He 

 employs it as follows (ibid., p. 810) : Portions of muscle 

 (gastrocnemius of frog) having been very carefully teased out 

 in fresh serum are treated for ten to twenty seconds with 

 nitrate of silver solution of 2 to 3 per 1000, and exposed to 

 bright light (direct sunlight is best) in distilled water. As 

 soon as they have become black or brown they are brought 

 into 1 per cent, acetic acid, where they remain until they have 

 swelled up to their normal dimensions (the swelling induced 

 by the acid serving to make up for the shrinkage caused by 

 the nitrate of silver) . They are then examined in a mixture 

 of equal parts of glycerin and water. 



This process gives negative images, the muscular substance 

 is stained brown, except in the parts where it is protected by 

 the nervous arborescence, which itself remains unstained. 

 The gold process gives positive images, the nervous structures 

 being stained dark violet. 



669. Nerve-endings the Bichromate of Silver Method. The 

 osmium bichromate and silver method of Golgi has been suc- 

 cessfully applied by RAMON Y CAJAL to the study of the ter- 

 minations of nerves and of tracheae in the muscles of insects, 



