192?] Swezy: Pseudopodial Method of Feeding 393 



to six hours. In physiological salt solution and various other media 

 that have been tried, the body of the flagellate tends to round up 

 immediately, becoming greatly distended and dissolving a few minutes 

 after being placed on the slide. 



These termites contained a species of Trichonympha and one of 

 Leidyopsis in great abundance. Both were found to be actively 

 feeding and full details of the process could be watched under the 

 microscope. 



A slide prepared in the manner described above presents a remark- 

 able picture of ceaseless activity and turmoil when viewed under a 

 1(5 objective with a low ocular. So narrow is the space between 

 the bodies of the flagellates that often flagellar activity is entirely 

 obscured and the resulting picture shows only a tangled mass of 

 writhing protoplasmic bodies, the movements and appearance of 

 which defy description. Near the outer borders of such masses 

 the number of individuals becomes somewhat lessened and here their 

 movements may be followed with greater ease and certainty. 



The outstanding feature in such a picture is the extreme mobility 

 of the flagellate 's body. When worming its way through a crowded 

 mass of its fellows, the change of outline is incessant, with such 

 changes reflected in the shape of the nucleus and protoplasmic con- 

 tents of the posterior part of the body. The endoplasm in the anterior 

 end seems to partake less of this movement, though this may be due 

 to the fact that it is very finely granular and contains no particles 

 that would catch the eye by their movement. The anterior portion 

 of the body, or that covered by the differentiated ectoplasm (Kofoid 

 and Swezy, 1919a), is in constant motion, waves pa.ssing spirally in 

 an antero-posterior direction. These movements are irregular, some- 

 times being of great frequency and amplitude, particularly when 

 an obstacle is met, at other times becoming slower, with only a slight 

 rise and fall of the surface. The posterior portion is usually more 

 passive and changes its shape only to meet the requirements of its 

 environment. When adverse conditions on the slide have slowed 

 down the motion of the flagellate, the protoplasmic movements cease 

 entirely, but the flagella continue their rippling motion for some time. 



Leidyopsis shows the same types of movements described for 

 Trichonympha, but the area of differentiated ectoplasm being much 

 smaller, both relatively and actually, its mode of progression is much 

 less striking than that of the larger flagellate. It exhibits two distinct 

 shapes of body. The first (fig. 1) is elongate with the posterior 



