134 SPECIFIC EXAMPLES OF SLIDE-MAKING 



The slides may remain in the saturated solution of Hthium chloride in 70 

 per cent alcohol for as long as is required, being subsequently passed directly 

 through the higher alcohols to xylene and mounted in balsam or some syn- 

 thetic substitute for it. 



This technique may, of course, be applied to accumulating and staining 

 selected sections from any series cut from any material. 



Summary 



1. Remove a 72-hour chick embryo from the egg and fix it as described in 

 Example 3. , 



2. Wash, dehydrate, clear, remove from paper support, embed in wax, and cut 

 a complete series of 10-ju sections throughout the whole embryo. 



3. Remove from the ribbon those portions from which sections are to be 

 mounted. 



4. Flood a clean slide with diluted Mayer's albumen. Place selected sections in 

 order, but without regard to symmetry, on fluid. 



5. Using two brushes, bring the two end sections into position. Fuse the edges 

 together in two places with a hot needle. Join the other sections in order 

 until a ribbon has been formed. Warm to flatten sections; drain and dry. 



6. Dewax dried sections and pass to 90 per cent alcohol through usual reagents. 



7. Stain until nuclei darken (1 to 3 minutes) in Ehrlich's acid alum hematoxylin. 



8. Take each slide individually and flush surface with 96 per cent alcohol from 

 a pipette. When sufficient stain has been removed, place slide in a satu- 

 rated solution of lithium carbonate in 70 per cent alcohol until blue. 



9. Dehydrate, clear, and mount in balsam. 



