394 



EVENINGS AT THE MICROSCOPE. 



gradually into a slender pointed tail at one extremity, 

 and at the other into a very long and equally slender neck, 

 which is terminated by a slight dilatation. The whole 

 is perfectly transparent, but the body is filled with nume- 

 rous minute globular vessels, or temporary stomachs. 

 The grace of its motion, as it glides along with a free 

 and moderately swift progression through the clear 

 water, or winds through the intricate passages of the 

 green conferva, throwing its long neck into elegant 

 curves, is very remarkable. There are, I see, two of 

 them, which, however, take no notice of each other, 

 even when passing close to each other ; the neck of one 



SWAN-NECK AND ITS DIVISIONS. 



is much longer than that of the other. Now and then, 

 when gliding along, the neck is suddenly contracted, but 

 not wholly, as if something had alarmed or displeased 

 the animal ; the body also can be swollen or lengthened 

 at pleasure ; it can move in either direction, but the 

 neck 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 infusion 

 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 fibre present, I 



