SOME MICROSCOPIC MUMMIES. 133 



beneath the force of the wind, we can well nigh fancy 

 that real moving waves pass over the surface of the field. 



Hurrying through the water, then, we find our 

 wheel-animalcules propelled by their ciliary lashes. As 

 the mouth opens below the wheels, we can understand 

 how particles of food are swept therein by the same 

 action which serves for movement. Then, when the 

 animalcule fixes itself, as Leeuwenhoek noticed, by its 

 tail-pincers (f) and still keeps its lashes in action, we 

 may note how, like a steamer moored to the quay, but 

 whose paddles continue to revolve, the animalcule's cur- 

 rents will act most forcibly in the way of food-getting. 



Our common rotifer is the type of a very large class 

 of animalcules, many of which, like itself, are free- 

 swimming in habits, while others build elaborate tubes 

 as dwelling-places, and exhibit more of the stay-at- 

 home philosophy than their roving neighbours. But 

 that feature which most excites our interest in this 

 curious class of wheel-bearing specks, is a certain 

 wondrous power they possess of surviving and re- 

 viving after being exposed to conditions of hardship 

 which would certainly extinguish the life and vitality 

 of all higher animals, and indeed of many other animal- 

 cules. Old Leeuwenhoek was the first to bring this 

 fact under notice, and numerous experiments have been 

 made after his day by way of confirming his observa- 

 tions. He shall tell us his story, once again, in his 

 own words : 



In October 1702, he observes, he caused the dry 

 debris of the house-gutters to be collected. About a 

 teacupful was gathered and placed in his desk in paper. 

 Then, " after the above-mentioned dry substance had 

 been nearly twenty-one months in the paper, I put into 

 a glass tube, of an inch diameter, the remainder of 



