Staining Blood, etc. 81 



of another slide spread it evenly over the centre of the 

 slip ; now put it away out of reach of dust to dry. When 

 quite dry flood the slide with stain A for three minutes. 

 Then wash with water, and flood the slide with stain B for 

 five minutes. Wash again with water, and allow the slide 

 to dry. Apply a drop or two of C. balsam and a cover- 

 glass. 



Blood of Mammals, Non-nucleated Corpuscles. 

 Spread some blood on a slide and let it dry. Then put the 

 slide in a turn-table, and run on a ring of any good cement ; 

 allow this to become perfectly dry, and then apply another 

 coat, which must be allowed to become nearly dry; now 

 clean a cover-glass and put it on th6 cement, and with a 

 needle press it down until it adheres firmly to the cement. 



Epithelium. Kill a frog, cut off its head and remove 

 the lower jaw. Open the abdomen and take out the 

 stomach, and slit it open. Place the head, lower jaw 

 and stomach in a 2 per cent, solution of bichromate of 

 potash for forty-eight hours. Then wash gently in water 

 until no colour comes away from the specimens. Now 

 place all three portions in picrocarmine for twenty- four 

 hours. Eemove the tissues from the carmine, and allow 

 the stain to drain away from them. Take the lower jaw 

 and scrape the tongue for squamous epithelium, and place 

 the scraping in a few drops of glycerine on a slide. Take 

 the stomach, remove some columnar epithelium from its 

 internal surface, and place it in some glycerine on another 

 slide. Then take the head for ciliated epithelium, which 

 will be found at the hinder part of the roof of the mouth ; 

 put some scrapings from this in glycerine on a slide as 

 before. Clean a slide and place a drop or two of Farrant's 

 medium on its centre ; take up a little of the epithelium on 

 the point of a needle, and put it into the medium. Now 

 apply a cover- glass, and with the needle-point press it down 

 until the epithelium cells are separated and spread evenly 

 between the cover and the slide. Set the slide aside for a 

 day or two, so that the medium may set. Then wash away 



