808 EVENINGS AT THE MICROSCOPE. 



their wayward traverses across each other, and intertwin- 

 ing their long thread-like tentacles, we will select one or 

 two for examination, as samples of their kindred. And 

 first let me separate this active little Beroe (Cydippe pomi- 

 formis), which I dip out with a tea-spoon and transfer to 

 this other glass jar, that we may watch its form and 

 movements unaffected by the presence of its companions. 



We see, then, a lit.tle ball, almost perfectly globular, 

 except that a tiny wart 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, — perfect transpa- 

 rency and colourlessness being its characteristics, so much 

 that it is not always easy to catch sight of the little crea- 

 ture, except when 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 proceed each 

 from the interior of a lengthened chamber, on each of two 

 opposite sides of the animal. Suddenly, on the slightest 

 touch of some foreign object, one of the threads is con- 

 tracted to a point and concealed within its chamber, but is 

 presently darted forth again. When the lovely globe 

 chooses to remain still, the threads hang downward, gra- 

 dually lengthening more and more, till their extremities 

 lie along the bottom of the jar, extended to a length of six 

 inches from the chamber. Then we see that this delicate 

 thread is not simple, but is furnished along one side, 

 throughout its length, at regular distances, with a row of 

 secondary filaments, which project at right angles from the 

 main thread. 



These secondary filaments constitute an important ele- 

 ment in the charm which invests this brilliant little crea- 

 ture. They are about fifty in number on each thread, and 

 some of them are half an inch long, when fully extended, 



