354 . EVENINGS AT THE MTCKOSCOPE. 



and most interesting, shaking an example or two oi 

 eacli kind into my glass jar of sea-water, where thej* 

 immediately began to frolic and revel as if still in 

 the enjoyment of unrestricted liberty. And here they 

 arc 



Among tliese bright and agile beings which are 

 shooting their wayward traverses across each other, 

 and intertwining their long thread-like tentacles, we 

 will select one or two for examination, as samples of 

 their kindred. And first let me isolate this active little 

 Beroe {JJydippe pomiformis)^ which I dip out with a 

 tea-spoon and transfer to this other glass jar, that we 

 may watch its form and movements unafi'ected by the 

 presence of its companions. 



We see, then, a little ball, almost perfectly globu- 

 lar, except that a tiny Avart marks one pole, of the size 

 of a small marble, and apparently turned out of pure 

 glass, or ice, or jelly — according to your fancy — per- 

 fect transparency and colourlessness being its charac- 

 teristics, so much that it is not always easy to catch 

 sight of the little creature, except we allow the light to 

 fall on the jar in a particular direction. From two 

 opposite sides of the globe proceed two threads of 

 great length and extreme tenuity, which display the 

 most lively and varied movements. 



These filaments shall occupy us for a few moments. 

 We trace them to their origin, and find that they pro- 

 ceed each from the interior of a lengthened chamber, 

 on each of two opposite sides of the animal. Sudden- 

 ly, on the slightest touch of some foreign object, one 

 of the threads is contracted to a point and concealed 

 within its chamber, but is presently darted forth again. 

 When the lovely globe chooses to remain still, the 



