viii Contents. 



PAGE 



Nucleus of the Yorticella — Methods of Reproduction — 

 Ciliated Protozoa — Wheel-bearers or Rotifers — Their 

 Structure — The Common Rotifer — The young Rotifer 

 seen inside the old one — an Internal Nursery—" Differ- 

 entiation" and "Specialization" — Bisexuality of Roti- 

 fers — Their Zoological Position— Diversities in their 

 Appearance — Structure of their Gizzard — Description of 

 Rotifers 10 



CHAPTER HI. 



FEBRUARY.^ 



"Visit to Hampstead — Small ponds — Water-Fleas — Water- 

 Beetle— Snails — Polyps — Hydra viridis — The Dipping- 

 tube — A Glass Cell — The Hydra and its Prey — Chy- 

 dorus Sphsericus and Canthocamptus, or Friends and 

 their Escapes — Cothurnia — Polyp Buds — Catching 

 Polyps — Mode of Viewing Them — Structure of Polpys — 

 Sarcode — Polyps Stimulated by Light — Are they Con- 

 scious? — Tentacles and Poison Threads — Paramecium 

 — Trachelius — Motions of Animalcules, whether Autom- 

 atic or directed by a Will — Their Restless Character . 30 



CHAPTER IY. 



MARCH. 



Paramecia — Effects of Sunlight — Pterodina patina — Curi- 

 ous Tail — Use of a Compressorium — Internal Structure 

 of Pterodina — Metopidia — Trichodina pediculus — Co- 

 thurnia— Salpina — Its Three-sided Box — Protrusion of 

 its Gizzard Mouth 43 



