LIVING MATTEE IN " PBOTOPLASM." 35 



to each other, and the intervening layer of liquid, therefore, 

 very small. 



Analysis of Tetanus. Tetanic contraction was first observed 

 by S. Strieker, in colorless blood-corpuscles in lively motion, the 

 slide and covering-glass being closely attached to each other, at 

 the moment when the cover was lifted a little by the addition of 

 an indifferent liquid to the edge of the specimen. As soon as the 

 liquid evaporated, motion and locomotion set in once more. I 

 have produced the same condition by the addition of glycerine. 

 Tetanus is also observed in most of the colorless blood-corpuscles 

 and amoebae, immediately after their transportation to the slide, 

 evidently due to mechanical shock. Similar results were yielded 

 by the electric current. To call such a condition " rest," is cer- 

 tainty erroneous. 



Analysis of Investing Layers. The production of a continuous 

 layer of living matter around the protoplasmic mass and a hollow 

 nucleus can be explained by a hypothesis only (Fig. 9). Such a 

 layer is far from being an investing membrane, in the sense of the 

 old cell theory ; it is identical in every respect with the reticulum 

 present within the protoplasm. Its capacity of admitting exten- 

 sion is surprisingly great. The thicker this wall is, either around 

 the nucleus or around the protoplasm, the less is the capacity of 

 producing amoeboid motion or locomotion. Solid nuclei and 

 nuclei with a broad investing shell do not themselves move, 

 but are carried along in a mechanical, passive way by the 

 moving reticulum around. Coarsely granular protoplasmic 

 bodies with a very marked investing layer do not move. The 

 finer the reticulum, respecting its points of intersection, and 

 the thinner the covering layer of living matter, the more pro- 

 nounced is the capacity of amoeboid motion and locomotion. 



The continuous layer of living matter may at any time and almost instan- 

 taneously be transformed into a reticulum. A foreign body may be taken 

 into the interior of a protoplasmic body by offshoots embracing the foreign 

 mass, the distal ends of the offshoots then coalescing, and lastly at the proxi- 

 mal ends, the investing layer being converted into a reticulum. The thinner 

 a flat layer, or the more it is stretched, the more prone is it to fuse together 

 with neighboring formations of the same kind. Long offshoots of amoebae, f. i., 

 easily coalesce to form a coarse reticulum. Not all foreign bodies that are 

 taken into the interior of the amoeba can serve as a pabulum, as, f. i., carmine 

 or aniline granules, silicious shells of diatomes, etc. 



The bursting of the outer investing layer is necessary for the 

 extrusion of foreign bodies, or fat-granules, or a liquid. Such a 

 wound at the periphery of the protoplasmic body may heal imme- 



