Mesenchymal Activity in the Chicks. 67 



39 (1414) 



Mesenchymal activity as a factor in resistance against mouse 



sarcoma in chick. 



By Vera Danchakoff. 



[From Columbia University, George Crocker Special Research Fund, 

 New York City, F. C. Wood, Director.] 



The digestive capacity of a mesenchymal cell in the embryo and 

 of a connective-tissue cell in the adult organism has been recorded 

 many times in the literature. 



A mesenchymal embryonic cell, being a very mobile element, 

 will easily detach itself from the common mesenchymal syncytium, 

 and in the presence of a foreign body will ingest it. Under normal 

 conditions, such foreign bodies in the embryo are for the greater 

 part red blood-corpuscles. While the vascular channels in the 

 embryo are undergoing extensive rearrangement, erythrocytes 

 are frequently found free amongst mesenchymal cells and ingested 

 by the latter. Whether or not an erythrocyte undergoing inges- 

 tion is still alive, we do not know. It is a highly differentiated 

 cell, in an unfavorable medium while outside the vessels, and with 

 no further power of proliferation. 



The ingested blood-cell undergoes within the phagocyte (of 

 mesenchymal origin) a series of chemical changes, some of them 

 demonstrable under the microscope, which transform it into a 

 structureless mass of protein and result in complete digestion. 

 The embryonic mesenchymal cell, therefore, not only is able to 

 synthesize proteins at the expense of amino-acids, but has itself 

 a digestive power. The intra-cellular digestive capacity of a 

 mesenchymal phagocyte may give us a basis for the understanding 

 of other aspects of a similar activity. Thus, chondroclasts, 

 osteoclasts, and clasmatocytes, which are but modified mesen- 

 chymal cells, exercise a digestive power, either intracellular or 

 extracellular. 



The mesenchymal embryonic cell is capable of digesting its own 

 proteins in the form of dead cells and possibly some living cells 

 which have lost their normal correlations with the tissues of the 



