REAGENTS AND RED CELLS. LEUCOCYTES. 59 



Effects of reagents. Applied by irrigation. 



Water. Cells lose their distinctness and the colouring 

 matter is dissolved. The outlines of single cells are still 

 recognisable where they are few in number. Note any change 

 in their shape and size. 



Syrup. 20 P>C - solution Cane sugar. Note the result of 

 exosmosis on their shape. 



Tannic acid strong solution and Boracic acid 2 p<c - solution. 

 Compare their effect upon the pigment, which is disseminated 

 as granules within or without the cells. 



Salicylic acid. Half saturated solution in alcohol. Compare 

 with the actions of tannin and of boracic acid. 



Acetic Acid. Watch the earliest effect of the reagent and 

 compare its effect on amphibian and human blood and on the 

 nucleus in the former. 



Leucocytes, white or colourless blood corpuscles. 



Fresh blood shielded with oil. Human blood should be received on 

 a warmed slide, covered, and be placed on the hot stage. 



Search for three varieties : (1) Large finely granular. 

 (2) Large coarsely granular. (3) Small round (Lymphocytes). 

 Examine minutely their cytoplasm, the nucleus is not clearly 

 discernible. 



Amoeboid movements. Find cells in active movement ; note 

 the variety to which they belong. The resting spherical form 

 is lost, the cell becomes irregularly extended by a flowing 

 motion, with resultant changes of shape and position. Sketch 

 the outline every 30 seconds. 



