INFUSORIA. 395 



turned the glass cover so as to alter the position of the 

 contents. On again looking, the Swan was in a clear part 

 of the field, but in the form of a dark globose mass, the 

 neck being entirely contracted. It was quite still, except 

 a continual slight alteration of the form by the protrusion 

 or contraction of parts of the outline. The body seemed 

 full of minute globules, .set in a granular mass of a 

 blackish hue, and the outline was not a continuous line, 

 but formed a multitude of rounded elevations. Presently 

 it protruded the clear neck, but only for a short distance, 

 and then retracted it as before ; when the only indication 

 of the presence of this organ was a depression in one 

 part of the surface, somewhat like the mouth of a closed 

 Actinia, where there was a slight but incessant working, 

 very much like the irregular motion on the surface of 

 boiling water, in miniature; there was also an indistinct 

 ciliary action at this part, not of rotation, nor of vibration, 

 but a sort of waving. At this point I had occasion to get 

 up from the table, and though I was not away more than 

 a minute, on my return I observed a strong constriction 

 around the middle of the bodv. It was transverse, for 

 the depressed and ciliated mouth was at a point exactly at 

 right angles to the constriction. From the depth to which 

 this latter extended in so few minutes, I supposed the 

 process of separation would be very rapid ; for I could 

 very soon see a line of light all across at intervals, and 

 the two halves seemed to slide freely on each other. Yet 

 they remained long without much apparent progress, or 

 even change, except that the anterior half at one time 

 threw forth its neck a short distance ; at this time it 

 looked extremely like a bird, bridling up its lithe neck and 

 swelling bosom; while, to make the resemblance perfect, 

 it began to imitate the action of a fowl picking up grain, 

 bobbing its head hither and thither : so curious are the 

 analogies of nature ! Along the dividing line there had 

 appeared very early in the posterior half a distinct ciliary 



