442 EVENINGS AT THE MICROSCOPE 



usually goes foremost, extended in the direction of the 

 motion, and seems to be used to explore the way. 



I had once an opportunity of seeing the process of in- 

 crease by spontaneous self-division in this creature. It 

 was an unusually large specimen, found in an old infu- 

 sion of sage leaves. When I discovered it, it was darting 

 about its long neck in the most beautiful contortions. As 

 it was partly hidden by the vegetable fibres present, I 

 partly turned the glass cover 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 



SWAN-NECK AND ITS DIVISIONS. 



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 black- 

 ish 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 Ac- 

 tinia, 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 



