382 H. H. Anderson — Description 0/ Anoplophrya seolosomatis. [No. 4, 



crystalline, particles of different sizes were seen in it. In most cases, 

 as the body lost its vitality, the granular portion of the endoplast con- 

 tracted and became surrounded by a clear space. The surface of the in- 

 fusorian is densely ciliated and finely striated in a longitudinal direciion. 

 The contractile vesicle was observed with great difficulty ; in many 

 specimens examined in the body of their host it could not be seen at 

 all ; in some, however, it was faintly seen, and in some very clearly ; in 

 no case was more than one observed, though numerous individuals 

 passed under careful examination ; it is situated centrally above the 

 endoplast. 



"When watched in the alimentary canal of the jEolosoma, the Anoplo- 

 phrya were usually stationary, with cilia in constant vibration. When 

 by the crushing of the worm they were forced out, they swam vigorously 

 forward for a short distance and then, in almost every case, reversed their 

 motion, usually getting back again close to the point they had started 

 from ; but they seemed at once to lose the power of motion, though their 

 cilia kept vibrating for a long time. Specimens which had got right 

 away into clear water soon became quiescent and lost their shape ; 

 those which were surrounded by the contents of the alimentary canal 

 kept their power of motion for a long time, in one case for over half an 



hour. 



The multiplication by transverse fission is interesting as resembling 

 the process that takes place in Anoplophrya nodulata. A number of 

 different specimens in different stages of division were seen and drawn. 

 The first form showed a constriction of the posterior extremity, about 

 the last quarter of the endoplast being divided off. Judging from the 

 various specimens in intermediate stages observed, this constriction 

 gradually increases till the part which is being divided off is about 

 twice as broad in its broadest part as it is at the point where it is attached 

 to the parent form. In numerous cases a second constriction and ap- 

 pearance of fission anterior to the first was seen, the segments re- 

 maining attached. It was noticeable that the individuals in process 

 of division were far larger than those not being divided and also that 

 the segments were very much smaller than the parent form. The seg- 

 ments were approximately equal to one another, though in all cases the 

 middle one, that is to say, the one divided off latest, was somewhat larger 

 than the hinder one. The hinder segment was in one case observed to 

 break off from the others and commence an independent existence. 



Though for some time I was unable to find any of these Anoplophrya 

 in ^olosoma taken from the same glass as those were in which I had 

 found them swarming weeks before, I noticed numerous very small 

 ciliated bodies, which were in some cases in very vigorous motion. 



