66 LIBBIE H. HYMAN 



towards the posterior end. Figure 6 is similar to figure 5. 

 Figure 7 is one of those infrequent cases where the pseudopodium 

 formed after the application of the cyanide arises at the side 

 of the body and not at the posterior end. 



3. Experiments with ^ to tV molecular KN C . When exposed to 

 these concentrations, the amoeba begins to contract slowly. In 

 this contraction the ectoplasm becomes greatly wrinkled and 

 corrugated. There is no attempt at pseudopod formation. 

 The old pseudopodia are recognizable for some time as blunt 

 projections. If disintegration occurs while the pseudopodia are 

 still identifiable, it involves the pseudopodia first as usual. 

 Generally, however, disintegration takes place only after the 



Fig. 8 Disintegration of amoeba in i S molecular KNC. a shows corrugated 

 form assumed by the amoeba in this dilution; b and c, disintegration of the short 

 pseudopodia. 



amoeba has contracted to a spherical mass from the surface of 

 which there project numerous short pseudopodia which are 

 really the corrugations produced by the contractions (fig. 8a) . 

 In this condition all trace of the previously existing pseudopodia 

 is lost. In the disintegration of these spherical masses, the sur- 

 face corrugations gradually melt away, the longer and more 

 slender ones first, the disintegrated protoplasm remaining as 

 little droplets (fig. 8) . The entire surface of the sphere then dis- 

 solves away simultaneously, and the protoplasm by a sudden 

 expansion which is almost an explosion spreads out into the sur- 

 rounding water. The entire process requires some twenty to 

 forty minutes. 



4. Experiments with more dilute solutions. In dilutions some- 

 what greater than ^ molecular, the amoeba gradually assumes 

 the spherical form studied with short pseudopodia as in the pre- 



