THE LIVING SUBSTANCE. 



117 



of each individual is in ceaseless change of position with respect 

 to the mass of that unit; and further, with respect to the mass 

 of the colonial organism as such; besides which, there is the 

 ceaseless interchange of substance and function between ecto- 

 sarc and endosarc, and finally a ceaseless interchange of sub- 

 stance between the units. The units are covered throughout, 

 over their whole periphery, by the usual ectosarcal formation. 



[106] For the substance as such, then, there is no quiet nor 

 any persistence of position. Yet each portion of that substance, 

 wherever it passes or pauses, knows where it is and how to 

 play its part as citizen-substance of the coalition. Surely this 

 is more marvellous than the imagined stable diversity and 

 interaction of Metazoan cells, if indeed we still dare to say that 

 in them is greater actual repose of the substance as such 

 beneath the mask of form of organ and organism. 



The final touch to wonder is given when it is seen that the 

 units of this coalition are, as organisms, surrounded at all points 

 exactly as usual by their normal external environment, for at 

 first they are joined by their filose processes between and 

 around which, as later with respect to the bands, the water 

 freely passes. 



If, in the starfish ^gg, the phenomena are such as to incline 

 one, if one does not bow to the mosaic hypothesis, to think 

 there must be in the ^gg some coordinating area or factor 

 which it, as organism, possesses, — a sort of brain direction 

 owned by all the cells in common, — how can one bring such 

 an interpretation into play here, where the units are not parts 

 of a single mass formed at one time by one parent, nor even 

 indirect products of two which peculiarly dovetail their prop- 

 erties and "ids "; but is a coalition of stranger organisms. In 

 which should one say the control resides.-' Or shall we think 

 one unit perhaps assumes entire direction while the rest hold 

 in abeyance their control power as they hold part of their 

 pseudopodial formation .J" Then how is this common harmony 

 of action got at.? And how reconcile it with the retention in 

 part of control by the units.? For it is hard, too hard indeed 

 for me, to believe that the single controlling centre would be 

 able to manage this feat. Finally, how can the units as such 



