400 PKACTICAL HISTOLOGY. [XXXVIIL 



(a.) Inject AgN0 3 (.5 per cent.), and isolate arteries, veins, 



and capillaries ; best from the intestine. Mount in 



balsam. 

 (b.) Show the effect of acetic acid on one of the larger vessels 



of the mesentery. 

 (c.) Methylene-blue injected into the vessels shows the lining 



endothelium and nerve-fibres. 



20. Blood and Blood-Corpuscles. 



(a.) Osmic acid and picro-carmine (p. no). 



(b.) Cover-glass preparations stained by eosin in glycerine and 

 then in logwood. Or other dyes or double stain 

 (p. 114). 



(c.) Cover-glass preparations stained by methylene-blue for the 

 nuclei. Pass the cover-glass three times through the 

 flame of a Bunsen-burner before staining. 



(</.) The colourless corpuscles may be stained in the methylene- 

 blue specimens, but they may be specially stained by 

 eosin-glycerine or indulin-glycerine, which stain certain 

 granules in their protoplasm (p. 402). 



21. Fibrin (p. 119). 



22. Marrow. Squeeze out same. 



Examine fresh in NaCl (.6 per cent.) with methyl-violet. 



Cover-glass preparations stained with eosin-glycerine and 

 logwood (p. 1 88). The easiest way is to pass the cover- 

 glass with its adherent film of marrow three times 

 through the flame of a Bunsen-burner before staining. 



23. Motor Nerves to Muscles. Gold method or methylene- 

 blue (p. 219). 



B. From a Mammal. 



If a mammal, e.g., rat or guinea-pig, or part thereof, be given 

 from which to prepare specimens, the methods are much the same 

 as those described above. 



24. Areolar Tissue. (a.) To show its histological elements the 

 best plan is to inject under the skin, by means of a hypodermic 

 syringe, some fluid which will form an artificial oedema, e.g., methyl- 

 violet in normal saline, osmic acid (i per cent.), silver nitrate 

 i : 300. The first of these fluids does not alter the tissues. Excise 

 a piece and examine it in the same fluid. 



(b.) Use the " semi-desiccation " method with a small piece snipped 

 off" and spread out on a slide. 



(c.) Cell-spaces by means of AgN0 3 (p. 162). 



In addition to the methods described at p. 161 and p. 162, use 

 acetic acid to show elastic fibres ; magenta to stain the latter. 



25. Tendons, e.g., rat (p. 168), and methods at p. 397. 



