448 



CHARLES H. SWIFT 



2. One per cent aqueous solution potassium permanganate 

 about 5 seconds; this time, however, is dependent upon the age 

 of the embryo and the thickness of the section. 



3. Five per cent aqueous solution oxalic acid about 5 seconds 

 or less. 



4. Stain 3 to 6 minutes at 60°C. with Altmann's anilin-acid 

 fuchsin. 



5. Wash thoroughly in water. 



6. Differentiate with Wright's blood stain. This stain is al- 

 lowed to remain on the section 10 to 20 seconds. 



7. Remove the excess of the differentiator with 95 per cent 

 alcohol. 



8. Absolute alcohol, toluol and into balsam. 



This method gives a preparation which looks like a Benda 

 stain and has the advantage that it is much more rapid. All 

 sections were cut 4^t in thickness. Table I will show at a glance 

 the number of embryos employed, their age, together with the 

 methods used in fixation and staining. 



TABLE 1 



