xv PHAGOCYTOSIS IN THE FROG 71 



(b) Stain in aniline gentian -violet for half an hour. 



(c) Wash in '6 per cent saline solution: 



(d) Place in Gram's iodine solution for half a minute. 



(e) Again wash in '6 per cent saline solution. 



(/) Now wash in absolute alcohol for half a minute. 

 (g) Quickly pass through 3 per cent hydrochloric acid 

 alcohol (five to ten seconds). 



(h) Again wash in absolute alcohol (ten seconds). 



(i) Stain with cosine (eosine -5 gramme, 50 per cent 

 alcohol 100 cc.) for a second or two. 



(Jc) Wash in absolute alcohol, till the section is pink and 

 apparently quite free from gentian-violet. 



(I) Clear in xylol and mount. 



Here again, as previously mentioned, the various 

 solutions for washing, etc., are best kept in wide-necked 

 bottles or pots. 



Phagocytosis 



A pithed frog has been inoculated under the skin of the 

 thigh, or into the peritoneal cavity, with a few drops of a 

 young broth culture of anthrax bacilli. 



Four to six hours later examine its lymph or peritoneal 

 fluid. 



(1) Examination in a hanging drop. 



(a) Pass a fine capillary tube under the skin of the 

 thigh, or into the peritoneal cavity, and remove some of the 

 fluid, and carefully, avoiding air-bubbles, blow a drop on to 



