244 MACERATION AND DIGESTION. 



smooth muscle. Twenty-four hours' maceration will suffice 

 for nerve tissue. About 10 c.c. of the solution should be 

 taken for a cube of 5 mm. of the tissue (Raiivier). 



508. Bichromate of Potash. 0'2 per cent. 



509. Muller's Solution. Same strength. 



510. Miiller's Solution and Saliva (see above, 504). 



511. BROCK'S Medium (for nervous system of Mollusca; 

 Intern. Monatsch. f. Anat., i, 1884, p. 349). Equal parts of 

 10 per cent, solution of bichromate of potash and visceral 

 fluid of the animal. 



512. MOBIUS' Media (quoted from Zeit. f. wiss. Mik., iii, 3, 

 1886, p. 402). 



1. 1 part of sea- water with 4 to 6 parts of 0'5 per cent, 

 solution of bichromate of potash. 



2. 0*25 per cent, chromic acid, 0*1 per cent, osmic acid, 

 O'l per cent, acetic acid, dissolved in sea- water. For Lamelli- 

 branchiata. Macerate for several days. 



513. Osmic Acid. 0*1 per cent., for from a few minutes to 

 a fortnight (cortex of cerebrum, Ilmdfl eisch) . May be fol- 

 lowed by maceration in glycerin. 



514. Osmic and Acetic Acid (the HERTWIGS' Liquid, Das Ner- 

 vensystem u. die Sinnesorgane derMedusen, Leipzig, 1878, and 

 Jen. Zeitschr., xiii, 1879, p. 457; Journ. Roy. Mic. Soc., iii, 

 1880, p. 441, and (N.S), iii, 1883, p. 732). 



0*05 per cent, osmic acid .... 1 part. 

 0*2 ,, acetic acid . 



Medusse are to be treated with this mixture for two or 

 three minutes, according to size, and then washed in repeated 

 changes of O'l per cent, acetic acid, until all traces of free 

 osmic acid are removed. They then remain for a day in O'l 

 per cent, acetic acid, are washed in water, stained in Bealu's 

 carmine (in order to prevent the osmium from over-blacken- 

 ing and to assist the maceration), and are preserved in gly- 

 cerin. 



For Actinise, the osmic acid is taken weaker, 0*04 per cent. ; 

 both the solutions are made with sr;i-\Y;itrr ; mid tin- w.-isliing- 

 out is done with 0*2 per cent, acetic acid. If the maceration 



