Some Curious Tube-builders. 



out to many times their own length. Here are some 

 riding at anchor, moored by delicate threads spun 

 from their toes ; and there are others flashing by in a 

 glass armour, bristling with sharp spikes or ornamented 

 with bosses and flowing curves ; while, fastened to a 

 green stem, is an animal convolvulus that by some 

 invisible power draws a never-ceasing stream of victims 

 into its gaping cup, and tears them to death with 

 hooked jaws deep down within its body." While it is 

 impossible to take this idealistic plunge beneath the 

 surface, it is quite possible, with the help of collecting 

 bottle and microscope, to bring the strange denizens of 

 this pond within the range of our vision, and that is 

 what we will now proceed to do. 



Attached to the submerged stems and leaves of 

 water plants may often be found a microscopic builder 

 of singular beauty and interest. To the unaided eye, 

 the little tower within which this creature dwells looks 

 like a tiny stump about one-sixteenth to one-thirty- 

 second of an inch in length fixed at one end to the sur- 

 face of the leaf or plant stem. On placing a leaf to 

 which one of these tubes is attached in a watch glass 

 or shallow cell filled with water, and examining it under 

 the microscope, we shall find that the little stump, 

 now greatly magnified, is really quite a beautiful ob- 

 ject, and composed of numerous round pellets placed 

 in regular rows one on top of the other, like rows of 

 circular bricks. This is the home of the Melicerta, 

 the Brick-maker Rotifer. As we look at the rows of 

 neatly arranged bricks or pellets, the head of the Rotifer 

 begins cautiously to appear above the edge of its tower, 

 and then it suddenly thrusts forth and expands before 



