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morning, when I found the Volvox still living, although rather slug- 

 gish in its movements. The animalcule before mentioned was ex- 

 ceedingly lively, occasionally swimming about, but more frequently, 

 fixing itself by its extremity and thrusting its snout in every direc- 

 tion, it appeared to be feeding on the green granules, seizing them 

 with its jaws, and pulling at them with considerable force. I could 

 not perceive, however, that it succeeded in detaching any of them, 

 but among the contents of its intestines, there were several colour- 

 less balls of nearly the same size. Although the creature appeared 

 to use considerable force in thus pulling at the granules, I did not 

 perceive that the Volvox was particularly affected by it. The ciliary 

 movements of the latter still went on, although its motions were, as 

 I before stated, rather sluggish. The gelatinous mass I had 

 observed the evening before had now expanded, and manifested 

 itself as another animalcule, similar to the first, but rather smaller, 

 and very transparent ; it was also extremely active. On this day 

 they were seen by many persons, to whom I exhibited them as ob- 

 jects of unusual occurrence. The next morning (Saturday) the mo- 

 tions of the Volvox had almost entirely ceased, No ciliary move- 

 ments appeared, as small bodies in the water came close up to its 

 edge without disturbance, and it only occasionally changed its 

 position. The larger animalcule was sluggish, while the smaller 

 one was exceedingly lively, swimming rapidly and turning about in 

 eveiy direction. The liquid within the Volvox appeared to be more 

 viscid than on the former days, and there were also some small dark 

 bodies disseminated through it, due probably to the excrements of the 

 animalcules. In this state it was seen by Mr. Quekett, who confirmed 

 my supposition as to the unusual occurrence of the appearances now 

 described. The next morning (Sunday), about 8 o'clock, I again ex- 

 amined them, when the Volvox was evidently dead, and appeared to be 

 decomposing, as the granules were much smaller than usual, and no 

 longer presented a definite outline. There were also large spaces of 

 the surface entirely free from them. ,The agglomerations of gra- 

 nules were also ill-defined, and much smaller than on the preceding 

 days. The parasitic animalcules had contracted themselves into 

 rounded masses. The smaller one was perfectly motionless, but 

 there was a very slight ciliary movement in the larger one : this was 

 the last sign of life I perceived. During the day I examined them 

 at intervals, but they both remained perfectly motionless, and about 

 10 o'clock at night, having no doubt of their being dead, and wish- 

 ing, if possible, to preserve some trace of them, I opened the 



