RESTORATION OF CO-ORDINATED MOVEMENTS AFTER NERVE SECTION. 695 



of the remaining portions prepared with the rocking microtome. The sections were 

 mounted in series. 



The chief method of staining employed was that recommended by Stroebe ; # but, as 

 I had formerly some difficulty in getting adequate staining of the axis-cylinder by this 

 method, although closely following the directions given in Stroebe's paper, I give here 

 the steps of the process which I have followed, and by which fairly good differentiation 

 of the axis-cylinder has been obtained. The deviations from the method are principally 

 those of the time allowed for each step. 



1. After removal of the paraffin, the slide bearing the series of sections is washed 

 for a few minutes in running water, so as to displace the alcohol, and then placed in a 

 tube containing freshly-prepared saturated aqueous solution of anilin blue (Grubler's 

 for Stroebe's stain), in which it remains for twenty-four hours. 



3. It is then washed in running water for some minutes. 



3. It is next placed in a dish containing a solution prepared by adding 15 drops 

 of a 1 per cent, solution of caustic potash in absolute alcohol to 12 c.c. absolute alcohol. 

 The dish is rocked from side to side, and the blue stain is extracted from the sections, 

 and this process is continued until the sections have a blanched blue appearance, usually 

 about one minute or less. Formerly I allowed the sections to remain in this destaining 

 liquid too long, waiting for the appearance of the clear brown-red colour described by 

 Stroebe. That tint never appeared, and the sections, when examined, were found to be 

 over destainecl, and the axis-cylinders therefore badly differentiated. I found after- 

 wards that with thicker sections cut in celloidin, the sections did assume a brownish-red 

 tint in the destain, while the stain was removed in brownish-red clouds ; but with the 

 extremely thin sections cut by the rocking microtome, it is only at the moment that the 

 sections are placed in the liquid that a slight brownish-red cloud appears, after which 

 the blue of the section simply continues to fade. The obvious explanation of the 

 difference is that with the thicker sections the brownish-red altered stain is not so 

 easily washed out by the alcohol, and, remaining entangled in the tissue, gives the 

 section the brownish-red tint, while with thinner sections the altered stain is at once 

 washed out by the alcohol, leaving the bluish tint unaffected. 



4. The slide is then washed in running water for some minutes, when the intensity 

 of the blue is somewhat restored. 



5. It is then placed in a tube containing anilin-water-safranin solution, in which it 

 remains for half an hour. 



6. It is next rinsed in water, dehydrated rapidly in absolute alcohol, and treated 

 with oil of cloves. This is allowed to remain on till the red colour begins to fade, but 

 before the bluish colour reappears, when the oil is drained off. 



7. The clove oil is then washed off with xylol, and the sections mounted in 

 balsam. 



Much depends on stopping the extraction of the safranin by the oil of cloves at 



* Ziegler's BeiMige, 1893, vol. xiii. p. 160. 



