44 PROTOPLASM 



reaches so far towards the centre as to set aside any doubt 

 as to the reality of what has been described. 



The radiate arrangement of the particles of lamp-black 

 was first observed when I studied the action of the electric 

 current on the drops. Under the influence of the constant 

 current the radial striation as a rule appeared very soon ; 

 nevertheless I should not like to assume off-hand a closer 

 connection between this phenomenon and electrical pro- 

 cesses. 



4. Fibrous Structures in Drops of Oil-Foam 



In the ordinary drops of oil-foam, which showed well 

 the phenomena of streaming that are to be described later, 

 it was often observed that an appearance of fibres was 

 noticeable at the so-called centre of extension-currents, i.e. 

 at the spot where a current from the interior reaches the 

 surface and thence flows away superficially on all sides. 

 The fibres followed the paths of the currents in their course, 

 and hence resembled to some extent a bundle of sheaves 

 passing out from the interior to the surface, where they 

 spread out. This appearance was naturally not immut- 

 able, but became modified in details more or less, since the 

 spot in question was the seat of continuous streaming move- 

 ments. 



If the very much thickened and exceedingly viscid olive 

 oil, already mentioned on p. 20, was worked up with K. 2 C0 3 

 into froth-drops in the way known to us, there were formed, 

 as has been already described, finely structured foams of 

 great viscidity and transparency, but quite good in other 

 respects. Since, however, they take the shape of irregularly 

 lobed masses between the cover-slip and slide, and no longer 

 assume a spherical form like the ordinary well-prepared 

 froths, it is clear that they are no longer fluid, but rather 

 deserve to be termed of a solid nature, or at all events they 

 are in an intermediate condition of consistency to which the 

 term solid is more appropriate. This also follows from the 

 fact that these froth-drops do not show the slightest ten- 

 dency to streaming movements, and when squeezed or pressed 

 do not begin to flow. If they are drawn out by pressure 



