334 THE AMERICAN MONTHLY [Dec, 



The Action of Leucocytes Toward Foreign Material. 



By EDITH J. CLAYPOLE, 



AKRON, OHIO. 



In this pnper fhe results of some experiment? madein the lab- 

 oratory of Profes-or Gnge of Cornell University, during the past 

 year are bnefly set forth. The object of the exjieriments was 

 twofold. ]n the first place, to discover if possible the ultimate 

 fate of at least part of the great number of leucocytes that in 

 the an'mal lody continually pass away from the circulation? 

 and in the second place to find what part the leucocytes play 

 in the removal of foreign material from the body. 



In considering this second point the nature of the leucocytes 

 as entities in the economy of the animal system is of especial 

 importance. The Phagocyte Theory of the great JJussian mar- 

 phologist, Metschnikoff, is based on one of their peculiar pow- 

 ers, that of taking up foreign material by virtue of their amoe- 

 boid movemei t. These cells form the guardian army of the 

 body. They stand ever ready to ingest and remove all foreign 

 substances that enter the system, and on their ability to do so 

 depends, to some extent at least, the health of the animal. If 

 the invading forces are too strong, the animal becomes sick or 

 perhaps dies, but if victory is with the leucocytes normal condi- 

 tions are again established. 



It is not necessary, however, for the contest to become appar- 

 ent. It is continually taking place, often giving no external evi- 

 dence of its existence. 



Such is the Phagocyte doctrine as its founder taught it. As 

 in other cases of wide generalizations, these extreme views have 

 not been adopted by all. Those belonging to the more conserva- 

 tive party consider the protective part played by the leucoc3'tes 

 as small or merely incidental. The fact of the ingestion of the 

 foreign material remains established, however, and on the 

 strength of this knowledge the following experiments were made, 

 the results of which are briefly presented. 



Under as nearly normal circumstances as possible, a smaP 

 quantity (i-1 c. cm.) of a mixture of lamp-black and gum ara- 

 ble suspended in normal salt solution, was hypodermically in- 

 jected into the abdominal cavities of the sal imanders, Necturus 

 maculatus (Mud-puppy) and Cryptobranchus aUeghaniensis (Hell- 



