

YitalHy and Organizaliun of Protoplasin. 37 



were' continuously furnished. Failing this supply its ])rolonged ex- 

 posure to the stimulating influences of the medium causes profound 

 disintegration and consequent contraction. This is demonstrated by 

 certain amceba that generally emit numbers of pseudopodia, which singly 

 expand and contract. The amoeba remains during such variformed 

 activity either, stationary, or moves quite irregularly by means of its 

 body being dragged along in the wake of one or the other of its expand- 

 ing or contracting pseudopodia. At times, however, such aniooba come 

 to form one single pseudopodium involving their entire substance, in 

 which case they move straight, along, head foremost, through space, 

 exactly like the ovoid being above described. I have depicted such an 



< amoeba in Pflueger's Archiv, Yol. XX Y, Fig. IX. I have also seen ) 

 Arcella Ehby and Difflugia pyriformis move at times straight along in 

 the same manner. 



The phenomena of vital motility prove conclusively that protoplasm 

 is a unitary substance, all parts of which are interdependently bound 

 together through wdiat is called chemical affinity, and its vital manifesta- 

 tions are, consequently, due to chemical processes. The living substance 

 being, moreover, a chemjcally cumulating substance, is therewith of 

 difl'erent chemical constitution in its sundry ascending parts, though . f cn^Cl/\^v{ 



I forming altogether a unitary whole. Best manifest in such amoeboid " 



beings as form one continuously flowing pseudopodium, the living sub- 

 stance is seen to assume by dint of its vital activities, and its interactions 



Y with the medium, a bipolar and bilateral shape. These intimate con- 

 stitutional properties of the living substance sufficiently account for the 

 hitherto mysterious phenomena of "polarity" and "bilaterality" found 

 to exist in plants and animals. They receive here their scientific ex- 

 planation by recognizing that the living substance necessarily assumes 

 a bipolar and l)ilateral form as a consequence of its all -involving cycle 

 of chemical activities induced by its relations to the stimulating influ- 



_ences of the medium. 



In 1880 I expressed these fundamental biological facts, which I had 

 discovered during my protoplasmic investigations, in the following 

 terms : "The protoplasmic projection, with its chemically cumulating 

 substance, highest at the apex, next high at the' circumference, and with 

 its direct dependence on the digesting substance, constitutes the primi- 

 tive zooid, the veritable animal unit. All essential divisions and direc- 

 tions j3f organization are predetermined and foreshadowed in its ra,cdg- 

 cuTar constitution and activity. The entoderm and ectoderm, the longi- 

 tudinal axis with its cephalic and acephalic pole; the transverse axes, 

 that remain equal when the animal does not creep ; but that get dis- 

 tinguished in size and import through the establishment of a dorso- 

 ventral dift'erentiation, when the animal does creep ; all these funda- 

 mental tendencies of organization are contained in the specific^ flow of 

 theliying substance, and are invariably expressed in the shape of a proto- 

 plasmic projection." Mind, "The unity of the organic individual." 

 This interpretation of the primitive, formative factors of organiza- 



