240 



PHAGOCYTOSIS IN THE LOWER ANIMALS 



method by which intruding particles are dealt with in the animal 

 economy. And, further, they correlate in the clearest possible 

 way this " scavenging " of the tissues with normal processes of 



FIG. 47. DAPHNIA CONTAINING LARGE NUMBERS OF MONOSPOR/E. 

 (Metchnikoff.) 



FIG. 48. HIND PART OF DAPHNIA. 

 At a the spores of monospora are shown surrounded by leucocytes. 



digestion and nutrition. Take, for instance, the absorption of 

 the red blood-corpuscles of birds, which are very suitable for 

 research, being readily recognized (they are nucleated), non- 

 poisonous, and easily digested. Metchnikoff showed that these 



