CONTENTS xi 



PAGE 



(&) Fibrous Protoplasm ..... 255 



(I) 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 



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



(c) Contractility of the alleged Reticular Framework . 269 



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



(e) 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 Berthold, 



Quincke . . . . . .289 



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

 ment . . . . . .307 



On the Currents in the Water surrounding Amoebae, 



etc. . . . . . . .317 



(&) Independent Movements of Granules . . . 319 



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

 plasm ...... 323 



(m) Possibility of an Explanation of Muscular Contraction in 



this Way ...... 325 



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



LITERATURE ........ 331 



EXPLANATION OF THE PLATES ...... 341 



INDEX . 367 



