CONTENTS 





PAGE 



INTRODUCTION ... 1 



PART I 



OBSERVATIONS ........ 5 



A. Investigations upon Oil-Foams ..... 5 



1. Preparation and Structure of the Foams ... 5 



2. Some more exact Statements as to the Alterations in 



Volume of the Drops of Foam under the Influence 



of the surrounding Fluid . . . .38 



3. Radiate Appearances in the Drops of Oil-Foam . . 41 



4. Fibrous Structures in Drops of Oil-Foam . . .44 



5. The Durability of the Oil-Foams . . . .46 



6. The Phenomena of Streaming Movement exhibited by the 



Oil-Foams ...... 47 



7. The probable Explanation of the Streaming Movements 



exhibited by the Drops of Foam . . .61 



8. Streaming Movements exhibited by Drops of Foam in Cells 80 



9. Remarks upon Frommann's Experiments on Drops of Oil- 



Foam . . . ..... .82 



B. Investigations upon Protoplasmic Structures . ... 85 



1. Investigations upon Protozoa . . ' . .86 



Suctoria ....... 87 



Ciliata ....... 88 



Flagellata . . . . . . . 91 



Radiolaria. ...... 92 



Heliozoa ....... 93 



Marine Khizopoda with Calcareous Shells and Reticulate 



Pseudopodia ...... 94 



Gromia Dujardini, M. Schultze . . . . 101 



Amcebse . .106 



