76 HOilES UITOER THE SEA. 



About August or September, according to the warmth 

 of the season, the water is full of these Plutei. They 

 are scarcely distinguishable to the unassisted eye, partly 

 on account of their transparency, and partly by reason 

 of their minute size, which scarcely exceeds the thirty- 

 sixth of an inch in diameter. 



Their shape is very remarkable, and not easy of cles- 

 scription. 



Let the reader try to imagine a wooden office-stool 

 standing on four long diverging legs. Then, let there 

 be four rods rather longer than the legs, screwed into tho 

 edges of the seat, and diverging much farther than the 

 legs, so that their ends are off the ground. Then let 

 there be two short rods fixed to the under part of the 

 seat and pointing downwards, and two rather longer rods 

 fixed to the upper edge of the seat and pointing upwards 

 and outwards. Lastly, let a much thicker rod be fixed 

 into the middle of the seat and point directly upwards. 

 This will give some idea of the form of the Pluteus, 

 which has sometimes been compared to the frameAvork of 

 a skeleton clock. 



Now for its material. 



Change the whole of the stool, legs, and rods into 

 glass, except the seat. Let this be of white chalk, and 

 let a thread of the same material ran up the centres of 

 the rods nearly as far as their tips. Strange as it may 

 seem, this is the appearance of the Pluteus when viewed 

 under a microscope. 



During this phase of existence, the Pluteus enjoys con- 

 siderable power of locomotion. 



