SOME MICROSCOPIC FRIENDS. 127 



ceived with hesitation and surprise, was fully con- 

 firmed. It became known that the white corpuscles, 

 instead of leaving the blood-vessels as a matter of 

 rarity, executed that manoeuvre as part and parcel of 

 their ordinary life-work. They are seen to migrate 

 regularly from their protecting vessels, and are ob- 

 served to wander about, as it were, within the body, 

 each on a roving commission, apparently uncontrolled 

 by any of the familiar forces or conditions of the 

 frame. 



Matters remained at this stage of research for a 

 considerable number of years. Not so very long ago, 

 ardent observers, however, once again returned to the 

 history of these wandering blood-particles. I have 



Fig 26. A White Corpuscle of the Blood (1-5, forms assumed successively 

 by one and the same Corpuscle). 



always entertained an objection to quoting in popular 

 papers names which are technical in nature ; but, 

 possibly, there will be no great risk of startling any 

 of my readers if I add that these white blood-particles 

 are now known as " leucocytes ; " while, from another 

 characteristic of their life and labour, they have also 

 been named "phagocytes." 



Watching one of these living particles on a micro- 

 scope slide especially kept at the blood's own tem- 

 perature, we can see it literally to flow from one 

 shape to another. It imitates in this way the move- 

 ments of many an animalcule in the pools. We may 

 also see our independent white corpuscle seizing and 

 digesting food particles, as if, in very truth, it were 



