THE BUILDING ROTIFER 179 



If twenty-five, or even thirty, microscopes be used 

 in a hall, and their owners exhibiting to a large 

 number of people various forms of marine and pond 

 life, by far the greater number of people will be 

 assembled to see the ' brickmaker ' at work. Its 

 house is about one-thirtieth of an inch long and the 

 eightieth of an inch wide. It is most difficult to 

 obtain an accurate drawing of the ' brickmaker ' or 

 his house, nor up to the present does the problem 

 appear to be solved by photo-micrography, or photo- 

 graphing them through the microscope. 



Several forms of low life are a great puzzle to 

 naturalists, owing to the remarkable power which 

 they possess of resuscitation after they have been 

 dried to a powder and allowed to remain apparently 

 dead for some years. Building rotifer is said to be 

 one of these extraordinary creatures. Ehrenberg, the 

 celebrated German naturalist, conclusively proved this 

 by actual experiment. 



Rotifers have rudimentary nerve centres, muscular 

 fibres, and a system of vessels for the due circulation 

 of fluids through their bodies. Their digestive 

 apparatus is more perfect than that of many forms of 

 life that are more bulky. Instead of dividing and 

 sub-dividing, in order to multiply their species, they 

 have power to produce eggs, which are hatched in the 

 cigar-shaped home. The little creatures swim about 

 freely, but only for a time. In this respect they 

 resemble the young of the sponge, not in appearance, 

 but in their freedom from parental restraint. It was 



