CONTENTS IX 



CHAPTER X. 



PAGE 



The Intimate Structure of the Cell . . . . .176 



Introduction ; Beggiaioa alba ; Thioporphyra volutans ; Thiophysa 

 volutans ; Beggiatoa mirabilis ; Chromatium Okenii ; Achroma- 

 tiuni oxaliferum [Hillhousia mirabilis, Modderida Hartwigi) ; 

 Achromatium mobile ; Thiovulum Mulleri ; Thiovulum majus ; 

 Chromatium Linsbaiteri ; summary and conclusions. 



CHAPTER XL 

 Irritability ; Influence of Light ; Chemiotactic Phenomena . 193 

 Irritability : introduction ; methods of investigation ; influence 

 of light on the sulphur bacteria ; Engelmann's investigations ; 

 photokinetic after-effect ; shock movements ; valve action of 

 shock movements ; Molisch on shock movements. Distribution 

 of purple bacteria in the various colours of the spectrum ; effect 

 of colour on the absorption of light ; liberation of oxygen 

 by the purple bacteria ; effect of light on the growth of the 

 purple bacteria ; the function of light, photosynthesis ; the 

 directive effect of light ; summary. Miyoshi's experiments ; 

 Bengt Lidforss's work ; Molisch's experiments ; irritability and 

 environment. Buder's researches : ciliary movements, reac- 

 tion to light, shock movements, localization of area of 

 sensitiveness, interpretation of results, 



CHAPTER XII. 



The Mechanics of Ciliary Movement. The Thionic Acid 



Bacteria. The Phylogeny of the Sulphur Bacteria . 216 

 The mechanics of ciliary movement. Thionic acid bacteria ; intro- 

 duction, methods of culture; Thiobacillus thiopants ; Thio- 

 bacillus denitrificans : Thiobacillus thiooxidans ; organisms 

 isolated by Issatchenko and Salismowskaja, Thiobacilhis B., 

 Bacillus crystalliferitm. Bacterium retiformans, Pseudomonas 

 bipunctatum, Pseudomonas hyalina. Nomenclature of the 

 thionic acid bacteria. The phylogeny of the sulphur bacteria; 

 factors concerned in the evolution of the group ; summary. 



CHAPTER XIII. 

 The Colouring Matter of the Sulphur Bacteria . . . 232 



Introduction ; historical ; investigations of Lankester, Biitschli, 

 Molisch ; methods ' of investigation ; absorption spectra ; 

 colouring matter of Thioporphyra volutans; spectroscopic 

 analysis of colouring matter of Thioporphyra volutans: 

 spectro-photometric method of examination ; summary 



Bibliography ........ 



Index of Author's Names 

 Index of Organisms 

 General Index 



243 

 255 

 257 

 259 



