70 Marvels of Pond-Life. 



shaped, with one eye in its forehead, and a two-pronged 

 tail sticking out behind (the Euchlanis triquetra), also 

 served to occupy attention ; but a further search among 

 the myriophyllum revealed more treasures of the tube- 

 dwelling kind. These were specimens of that highly 

 curious Rotifer, the Melicerta ringens, who, not con- 

 tent with dwelling, like the Floscules, in a gelatinous 

 bottle, is at once brick maker, mason, and architect, 

 and fabricates as pretty a tower as it is easy to con- 

 ceive. The creature itself stands upon a retractile foot- 

 stalk, and thrusts out above its battlements a large 

 head, with four leaf-like expansions surrounded by 

 cilia. Between the lower lobes, or leaves, the gizzard 

 is seen grinding away, and above it is an organ, not 

 always displayed, and of which Mr. Gosse was fortunate 

 enough to discover the use. This eminent naturalist 

 likens it to the circular ventilator sometimes inserted 

 in windows, and he found it was the machine for 

 making the yellow ornamental bricks of which the 

 tower is composed. Pellet by pellet, or brick by brick, 

 does the Melicerta build her house, which widens 

 gradually from the foundation to the summit, and every 

 layer is placed with admirable regularity. 



In order to obtain the materials for her brickmaking 

 the Melicerta must have the power of modifying the 

 direction of the ciliary currents, so as to throw a stream 

 of small particles into the mould, which is a muscular 

 organ, and capable of secreting a waterproof cement, by 

 which they are fastened together. The result is, not to 

 produce anything like the tubes made by the caddis- 

 worms out of grains of sand, but entirely to change 



