STAINING AND PERMANENT MOUNTING [ CH. X 



In cutting one proceeds exactly as in \ 457 except that the block is kept 

 wet with castor-xylene and not with alcohol. The sections are arranged on 

 the knife and transferred to the slide in the same way as for alcohol section- 

 ing (J 457-458). 



For fastening the sections to the slide, as no water is present, one can add 

 the ether-alcohol at once. It is advantageous here to have a mixture of ether 

 2 parts and absolute alcohol one part for melting the collodion in these oil 

 sections. 



Allow the slide to remain in the air till the collodion begins to look dull, 

 then the slide may be transferred to a jar of xylene to remove the oil. From 

 the xylene it is transferred to 95% alcohol and then the slide is ready to be 

 stained, etc. as described below {I 461-471). 



Steps in Order for the Collodion Method. — g 451-460, 461-47 r. 



Name 



No. 



Animal 



Date 



Fixer 



Time of fix 



Washedin water 



67% ale 82 o„ ale. 



Decalc. (S 398 . 



67% ale S2% ale 



In toto stain 



Washed in 



67% ale 82% ale. 



95% ale 



Ether-ale 



1 y 2 % col $% col. ... 



6% col 8% col..._ 



Imbedded 



Chloroform 67% ale... 



Or castor-xylene 



Sections cut /('s 



Stains 



Mounted in 



Remarks . 



STAINING AND PERMANENT MOUNTING 



\ 461. Generalities on Stains. — From the standpoint of the object to be 

 stained, dyes may be divided into two great groups : 



(1 ) (a) Those which select out or differentiate certain parts of the tissue 

 and make them prominent. Such dyes are called then differential or selective. 

 If the nucleus is the part selected, the dye is frequently called a nuclear dye. 



(b) General or counter stains. These stain all parts of the tissue, and are 



