The rcl.itidtis of iiiil(){'li(iiiili'i;i .■iinl ntliii ivlo|i|,iMiiic ((iic-lil iicnf s etc. 4HH 



described scviinl tiims mitii no iiicri'iisc in (lie (l<|(tli «if tin- colniir 

 rcsuHs). 



7. Wash ill ;i(|. (list. ;iinl ictiirn tor a lew seconds Id the eopjiei' acetate 

 ill order to convert all of tiie dye into the co|i|>er hike. 



8. Wash af^ain several niimites in a((. dist. 



9. Dii'fereniiiile innlci- (lif iiiii'ro.scn|ie in Weij^'ert's boi'ax-ferricyanide mix- 

 ture diluted wilh h\(i vnlumes of water. 



10. Wash 6 to 8 Ins. in t;i[i water. 



11. Dehydrate in alcohol, clear in toluol, and mount in iialsain. 



Tn preparations iliade by this iiietlKMl the iiiitdclioiKJiia appear in 

 an extremely distinct and sharply cut maiiiiri' mi aci-diiiit n\' their 

 dark blue-black colour and of the cleariie.^^s ot tlie l)a(jk;4ri'Uiid. ."Mu-h 

 a preparation is shown in tig. 7. 



7. The acid fuchsin-methyl green method. — I have tuund that 

 in the nerve cell the most constant and satisfactory df all the mitu- 

 chondrial methods, is Bensley's acid fuchsin-iiiethyl green technifiue. 

 It gives clear pictures; and demonstrates specifically, in addition to 

 mitochondria, the three remaining known components of the cytoplasm. 

 I am also indebted to him for permission to publish the particulars 

 of this method, which are as follows: 



I. Fixation. 



1. Fix spinal ganglia of the pigeon for 2, 4, 8 or 16 hrs. in either the acetic 

 osmio bichromate mixture or Altmann's fluid (vide supra). 



2. Wash, dehydrate, clear, imbed and section as indicated in method 6. 



II. Staining. 



1. Pass down througii toluol, abs.. 95"/(|. 70" „ and 50" y ;dc. to ai]. dist. 



2. 1 7u ^^.■ soin, potassium permanganate, about 30 sec; but this time must 

 be determined by trials. 



3. 5"/u aq. soin, oxalic acid about 30 sec; but this time must also be deter- 

 mined by experimentation. The potassium permanganate extracts the 

 mordanting elements of fixation, i. e. the chrome salts and osmium : and 

 the oxalic acid removes the permanganate. (If thase mordants have not 

 been properly extracted the cells in the finished preparations will appear 

 dark and opaque.) 



4. Stain for 6 min. at 60" C in a staining jar containing Altmann's anilin 

 fuchsin, 



Anilin water 100 ccm, 

 Acid fuclisin 20 g. 



5. Einse in aq. dist. 



6. Differentiate by dipping in a I",'« aq. soin, of methyl green, or toluidin 

 blue, which stains the Nissl bodies more intensely. (If an excess of the 

 differentiator is taken up it is best to rinse in 95 "/o ale.) 



7. Drain, and pass through abs. ale. and toluol to balsam. (When the sec- 



31* 



