MARY JANE HOGUE 



MORPHOLOGY AND MOVEMENT 



At first the most noticeable difference between these cells is 

 their diversity in size. The amoebae averaged 21 /x in length 

 and were much smaller than the fibroblasts which measured 

 50 M in length. The exact size of the fibroblasts is hard to deter- 

 mine, as their processes are so thin and fine that their farthest 

 limits are difficult to determine. The amoebae always have a 

 definite outline, though they are continually changing shape. 

 Still another difference is that the amoebae can be observed to 

 move rapidly, while the movement of the fibroblasts is too slow 

 to be noticeable, though they do move as can be seen by watching 

 the growth of the culture from day to day. The amoeba moves 

 by lunging in one direction and then in another. The cytoplasm 

 is thicker and denser than in the fibroblasts where the processes 

 are very thin and flat against the cover-slip. 



In order to study the two kinds of cells together, the amoebae 

 and the bacteria growing with them were introduced by means 

 of a platinum loop on the cover-slip where the tissue cells had been 

 growing for from twenty-four to forty-eight hours. The amoebae 

 began at once to crawl actively around and over the fibroblasts 

 without apparently disturbing them. 



The tissue cells had to be kept at 39°C. The amoebae ordi- 

 narily live at room temperature, though, as I have already shown 

 (Hogue, '21), they can be kept at 35°C. for twenty-four hours, 

 after which they showed a decided tendency to encyst some time 

 during the following week, the encystment not following immedi- 

 ately on their removal from the high temperature. When the 

 amoebae were brought into the warm box, where the cultures 

 were examined microscopically, their rate of motion was greatly 

 increased. They were now moving rapidly, and continued to do 

 so as long as they were kept at this high temperature. 



REACTION TO BACTERIA 



The presence of the bacteria, which were chiefly non-patho- 

 genic bacilli serving as food for the amoebae, was very harmful 

 to the tissue cells. They evidently could not stand the toxic 

 effect of the bacterial waste products. In a few instances some 



