144 MARVELS OF POND-LIFE. 



and possess a marvellous power of changing their 

 shape. Those before us are named after this pro- 

 perty Stentor polymorphus^^ or Many-shaped Stentors, 

 and owe tlieir exquisite tint to numberless green 

 vesicles, or small cavities filled with colouring 

 matter like that of plants. This, however, is not 

 essential to the species which may often be found 

 of other hues. In size this Stentor varies from 

 a hundred and twentieth to one twenty-fourth of 

 an inch. It is entirely covered with fine cilia, 

 disposed in longitudinal rows, and round the head 

 is a spiral wreath of larger and very conspicuous 

 cilia leading to the mouth. 



Having observed the abundance of these creatures, 

 a few small branches to which they were appended, 

 were [)laced in the glass trough, and viewed with 

 powers of sixty and one hundred linear. Some had 

 tumbled down to shapeless lumps, others presented 

 broad funnel-shaped bodies; wdiile others stretched 

 themselves to great length like the^long, narrow 

 post-horns which still wake the echoes of a few old- 

 fashioned towns. The ciliary motion of the elegant 

 wreath was active and rapid, causing quite a stir 

 among all the little particles, alive and dead; and 

 when the right sort of food came near the corkscrew 

 entrance to the mouth, down it went, and if con- 

 spicuous for colour, was subsequently seen appa- 



* See Frontispiece. 



