Powers that are most serviceable—Estimated by Focal length—Length of Body of Microscope and its Effects—Popular Errors about Great Magnification—Modes of Stating Magnifying Power—use of an "Erector"—Power of various Objectives with different Eye-pieces—Examination of Surface Markings—Methods of Illumination—Direct and Oblique Light—Stage Aperture—Dark-ground Illumination—Mode of Softening Light—Microscope Lamps—Care of the Eyes[1]
CHAPTER II.
JANUARY.
Visit to the Ponds—Confervæ—Spirogyra quinina—Vorticella—Common Rotifer—Three Divisions of Infusoria—Phytozoa—Protozoa—Rotifera—Tardigrada—Meaning of these Terms—Euglenæ—Distinction between Animals and Vegetables—Description of Vorticellæ—Dark-ground Illumination—Modes of producing it—The Nucleus of the Vorticella—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—"Differentiation" and "Specialization"—Bisexuality of Rotifers—Their Zoological Position—Diversities in their Appearance—Structure of their Gizzard—Description of Rotifers[10]
CHAPTER III.
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—Chydorus Sphæricus and Canthocamptus, or Friends and their Escapes—Cothurnia—Polyp Buds—Catching Polyps—Mode of Viewing Them—Structure of Polyps—Sarcode—Polyps Stimulated by Light—Are they Conscious?—Tentacles and Poison Threads—Paramecium—Trachelius—Motions of Animalcules, whether Automatic or directed by a Will—Their Restless Character[30]
CHAPTER IV.
MARCH.
Paramecia—Effects of Sunlight—Pterodina patina—Curious Tail—Use of a Compressorium—Internal Structure of Pterodina—Metopidia—Trichodina pediculus—Cothurnia—Salpina—Its Three-sided Box—Protrusion of its Gizzard Mouth[43]
CHAPTER V.
APRIL.
The Beautiful Floscule—Mode of Seeking for Tubicolar Rotifers—Mode of Illuminating the Floscule—Difficulty of seeing the Transparent Tube—Protrusion of Long Hairs—Lobes—Gizzard—Hairy Lobes of Floscule not Rotatory Organs—Glass Troughs—Their Construction and Use—Movement of Globules in Lobes of Floscule—Chætonotus larus—Its mode of Swimming—Coleps hirtus—Devourer of Dead Entomostraca—Dead Rotifer and Vibriones—Theories of Fermentation and Putrefaction—Euplotes and Stylonichia—Fecundity of Stylonichia[54]