160 Autonomy of Cell-Organs 



ledges, jutting into the interior, are in the process of for- 

 mation there generally run strong currents which evi- 

 dently bring and distribute the requisite food. But this 

 differentiation in the granular plasm is, to all appearances, 

 controlled by a corresponding differentiation in the plas- 

 matic membrane. For, according to Dippel, the bands 

 which form the layers of cellulose, consist of an outer 

 hyaline band, which is thicker than the rest of the plas- 

 matic membrane, and, like^ the latter, cannot be stained 

 with iodine, together with an inner, moving layer of the 

 granule-bearing plasm, which takes a deep yellow tint 

 when treated with iodine. 65 The hyaline band is evi- 

 dently a differentiated part of the plasmatic membrane 

 which, on its inside is covered and nourished by the cur- 

 rent, and on its outside forms the ledges of the cell- 

 membrane. 66 



In naked protoplasts the cilia also bespeak an inner 

 organization of the plasmatic membrane. These are de- 

 scribed by Strasburger 67 for the swarm-spores of Vau- 

 cheria. Here all the cilia adhere to a denser part of this 

 layer; they appear to be embedded in it by a thick root. 



8. The Question of the Autonomy of the Limiting 

 Membrane 



While in cell-division, according to the type described 

 by Mohl, the multiplication of the limiting membrane by 



65 Loc. cit. pp. 57, 58. 



66 Strasburger's hypothesis that the growth of the cell-wall is 

 accompanied by a transformation layer by layer of the outermost 

 strata of the limiting membrane into cell-wall can, without difficulty 

 be combined with the assumption of the autonomy of this organ with 

 reference to the granular plasm, and therefore need not be discussed 

 in detail here. 



67 Strasburger, Studien uber das protoplasma, p. 400. 1876. 



