POND LIFE 



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rhythmically, and producing a vortex 

 current which catches, and carries down 

 on to the centre of the flower-like expan- 

 sion, minute particles of animal and 

 vegetable matter ; for these extremely 

 delicate hairs or cilia are the organs with 



A RED WATER MITE. 



which the Rotifer captures its food. 

 Should some larger denizen of the pond 

 flash past, the little flower-like head of the 

 Brickmaker instantly contracts, and dis- 

 appears within the protecting walls of the 

 tiny tube, only cautious!}' to reappear 

 when the danger has safely passed. 



If we watch very carefully we shall 

 be able to see how it forms the bricks 

 of which its tiny tower is built, and how 

 it places them in position. The bricks 

 are practically composed of the indigestible 

 portion of the Rotifer's food, which is 

 gradually collected round a curious little 

 " stud " on the neck of the animal. When 

 a sufficient supply has been accumulated 

 to form a brick, the Rotifer is seen to 

 elongate its neck, and bending over its 

 flower-like head, bring the neck-stud into 

 contact with the top of the tower, and the 

 newly formed brick is ])lace(l in position. 

 With just a little attention to see that 

 the water is kept sufficiently oxygenated, 

 these beautiful and remarkable Brick- 

 maker Rotifers may be kept in a small 

 aquarium for a considerable time, in a 

 healthy and active condition. A very 

 interesting experiment may be carried 



out, with the exercise of just a little care, 

 by placing a portion of a plant stem to 

 which some young Brickmakers are at- 

 tached, in a zoophyte trougli, and intro- 

 ducing into the water a small quantity 

 of crushed leaves of the water-plant, to 

 which a little aniline stain has been added. 

 Only a very little of the infusicjn is 

 necessary, and at the end of a few h(jurs, 

 if examined, the tiny tubes which are in 

 ]^rocess of building will be seen to have 

 one or more tiers of coloured bricks. 

 By this means, and with the exercise of 

 sufficient care in giving a fresh supply of 

 infusion of another colour daily, or every 

 other day, the little Rotifers may be 

 induced to build their towers so that 

 they are composed of layers of different 

 coloured bricks. 



One of the most magnificent of the 

 Rotifers to be found attached to the 

 submerged stems and roots of the water- 

 plants is the so-called Crown Animal- 

 cule {Stcphanoceras), which does not 

 surround its body with a tower like the 

 Brickmakers. When seen in a thoroughly 

 vigorous condition, with its wonderful 

 " crown " fully expanded, Stcphanoceras 

 is one of the most beautiful inhabitants 

 of the pond. Although a large pro- 

 portion of the Rotifers lead a sedentary 



A BKICKMAKEK ROTIFER'S "TOWER." 



existence, attached by their base to the 

 stem or leaves of some aquatic plant, 

 there are a very large number wiiich 

 lead a roving life, travelling through the 



