CHAPTER XII.

DECEMBER.

Microscopic Hunting in Winter--Water-Bears, or Tardigrada--Their Comical Behaviour--Mode of viewing them--Singular Gizzard--Wenham's Compressorium--Achromatic Condenser--Mouth of the Water-Bear--Water-Bears' Exposure to Heat--Soluble Albumen--Physiological and Chemical Reasons why they are not killed by Heating or Drying--The Trachelius ovum--Mode of Swimming--Method of Viewing--By Dark-ground Illumination--Curious Digestive Tube with Branches--Multiplication by Division--Change of Form immediately following this Process--subsequent Appearances