TABLE OF CONTENTS. 



INTRODUCTORY. 



Pages 

 A branch of Comparative Psychology little known. — Defini- 

 tion of Micro-organisms. — Their classification. — Main 

 groups of animal Micro-organisms. — Complexity of their 

 life of relation. — The Micro-organism riot simply an irrita- 

 table cellule 1-4 



THE MOTORY ORGANS AND THE ORGANS OF SENSE. 

 MOTORY ORGANS. 



Motility. — The pseudopod. — Opinion of M. Rouget relative 

 to the formation of pseudopods. — The vibratlle cilia. — 

 Their morphological significance. — Observations of Engel- 

 mann. — The movements of the vibratile cilia are subject 

 to the will of the animal. — Observations of M. Balbiani 

 upon the Didinium nasulum. — Experiments of Rossbach. 

 — The flagellura. — Diversity of its movements. — Observa- 

 tion of Biitschli upon the flagellum of the Glenodiniuin 

 cinclum. — Metabolic infusoria. — The granulous bands and 

 bright filaments. — The contractile vesicle. — The move- 

 ments of Bacteria and Gregarinas ■ 4-20 



THE NERVOUS SYSTEM. 



Absence of a central nervous system in single-celled organ- 

 isms. — Hypothesis of a diffused nervous system. — Obser- 

 vation of Gruber upon the Stentor in process of division. 20-22 



THE ORGANS OF SENSE. 



Organs of touch. — Organs of sight. — Ocular spot in Flag- 

 ellates. — Ocular spot of vegetable zoospores. — Experi- 

 ments of Klebs upon the structure of these spots. — The 



