22 



W. H. E M I G 



Crocein Scarlet 7B, C. I. No. 286, 2 minutes. 



Acid Fuchsine, C. I. No. 692, 30 seconds to 1 minute. 

 Whenever two of these dyes are mixed the amounts needed 

 are in direct proportion to the time interval required for the stain- 

 ing of each alone. Thus, mix ten parts of Sun Yellow with five 

 parts of Orange II, ten parts of Sun Yellow with one part of Acid 

 Fuchsine, or five parts of Orange II with one part of Acid 

 Fuchsine. In the following outline any of the eight mixed stains 

 may be tried with one of the three counterstains. 



Counter stains 



( 1 ) Aniline Blue 



(2) Niagara Sky Blue 



(3) New Methylene Blue 



Mixed stains 



Sun Yellow (10) and 

 Orange II (5) 



Sun Yellow (10) and 

 Crocein Scarlet MOO (5) 



Sun Yellow (10) and 

 Biebrich Scarlet (2) 



Sun Yellow (10) and 

 Crocein Scarlet 7B (2) 



Sun Yellow (10) and 

 Acid Fuchsine ( 1 ) 



Orange II (5) and 

 Biebrich Scarlet (2) 



Orange II (5) and 

 Crocein Scarlet 7B (2) 



Orange II (5 to 10) and 

 Acid Fuchsine ( 1 ) 



Staining procedure. Using sections of an earthworm, try one 

 of the mixed stains such as Sun Yellow and Orange II for five to 

 ten minutes. If the first mixed stain does not produce two colors 

 on the section, try another mixture. When two colors are ob- 

 tained, the mixture may be used with a counterstain. The problem 

 at this point is to find which of the three blue counterstains will 

 give the best result; it is taken for granted that from sufficient 

 experience in handling double stains the principle involved in the 

 procedure of counterstaining is understood. 



