CONTENTS xi 



PAGE 



(k) Fibrous Protoplasm ..... 255 



(Z) Theories concerning the Causes of Radiate Appearances . 257 



6. The Homogeneous Protoplasm and the Alveolar Theory . 262 



7. The Phenomena of Protoplasmic Movement in their 



Relation to the Alveolar Structure . . . 267 



(a) Theories as to the Causes of the Phenomena of Movement 267 

 (ft) So-called Contractility . . . . .267 



(c) Contractility of the alleged Reticular Framework . 269 



(d) Objections to the Theory of Contractility . . 270 

 () Hypotheses of Hofmeister, Sachs, and Engelmann . 271 



(/) Electrical Hypotheses of Velten and Fol . . . 279 



(g) Leydig's View of the so-called Hyaloplasm . . 280 



(h) Montgomery's Hypothesis . . . . 287 



(i) Hypotheses relating to Surface Tension ^erthold, 



Quincke ...... 289 



(/) My own View of the Explanation of AmcEboid Move- 

 ment ...... 307 



On the Currents in the Water surrounding Amoebae, 



etc. .317 



(k) Independent Movements of Granules . . . 319 

 (Z) Causes of Internal Displacements in the Alveolar Proto- 

 plasm ...... 323 



(m) Possibility of an Explanation of Muscular Contraction in 



this Way . . . . ... 325 



(ri) Rotational Currents in Plant Cells . . .327 



LITERATURE ...:..,. 331 



EXPLANATION OF THE PLATES . . . . . 341 



INDEX . 367 



