CHAPTER VIII.

AUGUST.

Mud Coloured by Worms--Their Retreat at Alarm--A Country Duck-Pond--Contents of its Scum--Cryptomonads--Their Means of Locomotion--A Triarthra (Three-limbed Rotifer)--The Brachion or Pitcher Rotifer--Its Striking Form--Enormous Gizzard--Ciliary Motion inside this Creature--Large Eye and Brain--Powerful Tail--Its Functions--Eggs