BLOOD CELLS 25 



Make a drawing of each kind of corpuscle after treat- 

 ment with each reagent. 



PHTSIOLOGT 



Mix together on the slide a drop of frog's blood and 

 a drop of normal salt solution, then examine with a 

 high power. 



a. Movements. — Do any of the corpuscles have the 

 power of movement from place to place, or do 

 any change their shape ? If so, how is the move- 

 ment effected? What sort of motion is it? Is 

 it comparable to that of any animal which you 

 have studied ? Put the slide on the warm-stage 

 and heat to the temperature of the human body. 

 Does the higher temperature make any differ- 

 ence? 

 Make drawings to show the direction of motion and 



changes of shape if any. 

 To this drop of diluted blood add a drop of water in 



which indigo or carmine has been ground, or, better, 



use a drop of diluted yeast. 



h. Ingestion. — Do any of the corpuscles ingest the parti- 

 cles of indigo or the yeast cells ? If so, how do 

 they do it ? Compare with the ingestion of food- 

 particles by the different kinds of Protozoa stud- 

 ied. Of what use could this property of the cell 

 be in the frog ? 



c. Effects of temperature. 



1. Cold. — Lay the slide on a piece of ice for five 



minutes, then examine, and compare the results 

 with those of a and 5. 



2. Heat. — Heat the warm-stage slowly to a degree 



