112 DR. ELIAS METSCHNIKOFF. 



The Ancestral History of the Inflammatory 

 Process. 



By 

 Dr. Elias llletsclinikoff.i 



Under the name of " phagocytes " I have recently described 

 certain cells which have the power of ingesting and sometimes 

 of absorbing food particles. This character of the mesoderm is 

 most marked where we find a number of amoeboid cells 

 devouring dead or degraded elements of the body of the animal 

 in which they live. Pathology already furnishes numerous 

 examples of the exercise of this function by white blood-cor- 

 puscles; only it has not been recognised that the inges- 

 tion of foreign matter by a blood-corpuscle is a true act of feed- 

 ing, and that the absorption of such a body (a red corpuscle, 

 for example) is comparable to digestion. The results of in- 

 vestigations of Invertebrates, and the fact that in Sponges a 

 great part of the whole function of nutrition is performed by 

 amoeboid cells of the mesoderm, while in Bipinnaria, Phyl- 

 lirhoe, &c., such cells function indirectly as absorbent organs, 

 made it probable that a similar intracellular absorption would 

 be found in the Vertebrate mesoderm. 



The tail of Batrachians is an object well adapted for proving 

 the truth of this supposition. During the early stages of its 

 absorption it contains a large number of amoeboid cells, within 

 which are seen remnants of nerve-fibres and muscle cells. 

 These cells may be seen in any quantity by simply teasing up 

 in serum or aqueous humour a piece of any tail in which 

 atrophy has commenced. Left undisturbed for some little 

 time, each cell throws out a number of fine, radiating pseudo- 



1 " Ou the Mesodermic Phagocytes of Certain Vertebrates," ' Biologisches 

 Centralblatt,' iii, 18, 15th November, 1883. 



