Ryder.] 1^^ [April 7, 



types of kinetogeny and statogeny, form-determining or morphogenetic. 

 Tlie development of the figure of the body of Amosba proteus is also par- 

 tially conditioned by cohesion to adjacent sui faces, and is also, to some 

 extent, pulled upon as a semifluid mass by gravity and flattened. The 

 vortical flux of its own particles through themselves also elongates it in 

 the direction of its own motion. This causes the anterior end of the 

 organism to present a tense, rounded outline, while its posterior end is 

 wrinkled, papilliform or uneven. The vortical flux of particles in tiie 

 centre of the body of the organism flow fastest while they gradually move 

 slower towards the surface where the ultimate and outermost layer is at 

 rest. Thus in every detail of its morphology do we discover that Amwha 

 is absolutely the creature of energy conditions. Its shape at every instant 

 of its existence is determined ergogenelically as we may speak of the 

 form -conferring forces developed from within as distinguished from those 

 of gravity, adhesion and cohesion that are operative from without. Even 

 the ideally perfect form of vortex motion of the particles of its substance 

 is disturbed and distorted by the interaction of this complex set of forces. 

 Moreover, since the physical properties of the different species of Amce- 

 boids are very diflerent, their kinelogenelic and slatogenetic characteris- 

 tics differ correspondingly, so that their behaviors are very different for 

 this reason. The profound ditlerences of form presented by their pseudo- 

 podia are to be partially accounted for on this ground, and partially on 

 the ground of the difteriug physical constitution of their substance. 



The phenomena of motion of plasma or cells may be generally compre- 

 hended under the term eytokinetic, their statical conditions under the 

 term eytostatic. In the same way the active and resting stages of nuclei 

 may be regarded as karyokinitic and karyostatic. The motion and rest 

 of the centrosomes of cells may be named as their astrokinetic and astro- 

 static conditions. These six terms, one of which is already in use, are pro- 

 posed in order to connect the phenomena of cell division with ergogeny in 

 general. The origin of the motion of the Amoeba is to be sought in its 

 own plasma ; it is therefore eytokinetic. The alternating periods of qui- 

 escence of Amffiba are cytostatic ; its spherical form in the encysted con- 

 dition is the lesult of a perfect cytostatic equilibrium in every direction. 

 These results are also ergogenetic ; that is, the changes of configuration 

 due to motion are kinetogenetic ; those due to a condition of temporary 

 statical equilibrium are statogenetic. 



Osmotic processes in combination with surface tension and reciprocal 

 pressures developed against adjacent structures develop the most mani- 

 fold changes of configuration. If osmotic pressure is the same in every 

 direction williin a cell or a mass of cells, a spherical figure results such as 

 that of Volvox. If, on the other hand, the equal internal pressures are 

 antagonized from without by unequal pressures at diflerent points corre- 

 sponding modifications of figure are developed. This is iliuslrdled in the 

 most manifold ways in the cells of plants and animals. Such modifica- 

 tions thus caused are largely statogenetic. 



